How to Use the Fdisk Tool and the Format Tool to Partition or Repartition a Hard Disk (255867)

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How to Use the Fdisk and Format Tools

Before you install your operating system, you must first create a primary partition on the hard disk (disk 1) on your computer, and then format a file system on that partition. The Fdisk tool is an MS-DOS-based tool that you can use to prepare (partition) a hard disk. You can use the Fdisk tool to create, change, delete, or display current partitions on the hard disk, and then each allocated space on the hard disk (primary partition, extended partition, or logical drive) is assigned a drive letter. Disk 1 may contain one extended partition, and a second hard disk may contain a primary or extended partition. An extended partition may contain one or more logical MS-DOS drives.

After you use the Fdisk tool to partition your hard disk, use the Format tool to format those partitions with a file system. The file system File Allocation Table (FAT) allows the hard disk to accept, store, and retrieve data. Windows 95 OEM Service Release 2 (OSR2), Windows 98, Windows 98 Second Edition, Windows Millennium Edition (Me), and Windows 2000 support the FAT16 and FAT32 file systems. When you run the Fdisk tool on a hard disk that is larger than 512 megabytes (MB), you are prompted to choose one of the following file systems:

FAT16: This file system has a maximum of 2 gigabytes (GB) for each allocated space or drive letter. For example, if you use the FAT16 file system and have a 6-GB hard disk, you can have three drive letters (C, D, and E), each with 2 GB of allocated space.For additional information about the FAT16 file system, click the article number below to view the article in the Microsoft Knowledge Base:
118335 Maximum Partition Size Using FAT16 File System
FAT32: This file system supports drives that are up to 2 terabytes in size and stores files on smaller sections of the hard disk than the FAT16 file system does. This results in more free space on the hard disk. The FAT32 file system does not support drives that are smaller than 512 MB.For additional information about the FAT32 file system, click the article number below to view the article in the Microsoft Knowledge Base:
154997 Description of the FAT32 File System

When you run the fdisk and format commands, the Master Boot Record (MBR) and file allocation tables are created. The MBR and file allocation tables store the necessary disk geometry that allows hard disk to accept, store, and retrieve data. For additional information about MS-DOS partitioning and a hard disk geometry overview, click the article number below to view the article in the Microsoft Knowledge Base:

69912 MS-DOS Partitioning Summary

Important Considerations Before You Use the Fdisk and Format Tools

Consider the following questions before you use the Fdisk and Format tools:

Is the hard disk new? If not, view the second question.
- Is this hard disk the only hard disk on your computer (master) or is this hard disk a second hard disk (slave)?
- Have you prepared the hard disk by following the manufacturer's instructions? It is important to set the jumpers and cabling according to the role of the hard disk (master or slave).
- Have you checked your basic input/output system (BIOS) to verify that it supports the hard disk or the second hard disk? If not, check the documentation that came with your motherboard, or contact the manufacturer. Typically, the BIOS has an auto detect hard disk setting that configures the drive, but you should verify this before you continue.
- What type of file system do you want to use? You can use either the FAT16 or the FAT32 file systems. If you are not sure which file system that you want to use, view the following articles in the Microsoft Knowledge Base:
  118335 Maximum Partition Size Using FAT16 File System
  154997 Description of the FAT32 File System
Does the hard disk already contain data?
- Have you backed up all of your important data? If not, back up your data before you proceed. When you run the fdisk command to create, delete, or change a partition, all of the data on that partition is permanently deleted. Note that you can view current partition information without deleting your data.
  
  For additional information about how to install the MSBackup utility, click the article number below to view the article in the Microsoft Knowledge Base:
  152561 How to Install Microsoft Backup
  View the Help file in the MSBackup utility for information about how to use this utility. If you want to use the MSBackup utility with a removable media device, view the following article in the Microsoft Knowledge Base:
  188575 How to Back Up to Removable Media Device Using Microsoft Backup
  Note that a backup utility is not included with Windows Me.
- Does the hard disk have a drive overlay or a disk management program? If your computer uses drive overlay software to enable large hard disk support, do not use the Fdisk tool until you have checked with the software manufacturer. If you are not sure, view the following Microsoft Knowledge Base article or contact the software manufacturer before you proceed:
  186057 How to Tell If Drive Overlay Program Is Installed in Windows
- Do you have the floppy disks or the CD-ROMs that are necessary to reinstall your software? Make sure that you have the software so that you can reinstall your programs after you partition and format your drive. If you purchased an upgrade for a program, make sure that you have the full version of the original program. Many upgrades for programs require a compliance check before you can install the upgraded product. If you cannot find the original floppy disks or CD-ROMs, contact the software manufacturer before you proceed.
- Do you have updated device backed up on a device other than the drive that you are about to format and partition? If you have installed an updated device driver for your peripheral devices (for example, modems, printers, and so on), make sure that you back up the new driver on a device other than the drive that you are about to format and partition so that you can reinstall it after you install your operating system.
Do you want to combine multiple extended partitions in one extended partition? If so, view the "How to Repartition and Format the Extended Partition and Logical Drives on a Hard Disk" section in this article.
Do you have a Startup disk? Windows 95, Windows 98, Windows 98 Second Edition, and Windows Me prompt you to create a Startup disk during Setup. If you do not have a Startup disk:
1. Insert a blank floppy disk in the floppy disk drive (drive A).
2. Click Start, point to Settings, click Control Panel, and then double-click Add/Remove Programs.
3. Click Create Disk on the Startup Disk tab.
4. After you create the Startup disk, you should test it. To test the Startup disk, insert it in the floppy disk drive, and then restart your computer. If you are using a Windows 98-based computer, the Startup menu is displayed. If you are using a Windows 95-based computer, a command prompt is displayed.
Do you need Real-mode CD-ROM support? Some CD-ROM drives require Real-mode device drivers. If you are planning to use Windows 98 on your computer, the Startup disk contains generic, Real-mode ATAPI CD-ROM and Small Computer System Interface (SCSI) drivers that can enable CD-ROM drives after you boot from the Windows 98 Startup disk. Note that these CD-ROM drivers may not work with all CD-ROM drives; they may work as a replacement if the Real-mode CD-ROM drivers that are included with your CD-ROM drive are not available.

NOTE: If you insert your Windows 98 Startup disk, restart your computer, you may not be able to change to the drive letter of your CD-ROM drive (usually one drive letter ahead of where the drive letter typically resides because there is a random access memory [RAM] drive created by the Startup disk), because these drivers do not work with your CD-ROM drive. View the documentation that is included with your hardware, or contact your hardware manufacturer to obtain the CD-ROM device drivers.

How to Partition and Format a Master Hard Disk

IMPORTANT: If you use the following steps on a hard disk that is not empty, all of the data on that hard disk is permanently deleted.

How to Partition a Master Hard Disk

To partition a master hard disk, run the fdisk command:

Insert the Startup disk in the floppy disk drive, restart your computer, and then use one of the following methods, depending on your operating system. For a Windows 98, Windows 98 Second Edition, or Windows Me Startup disk:
1. When the Microsoft Windows 98 Startup menu is displayed, select the Start computer without CD-ROM support menu option, and then press ENTER.
2. At a command prompt, type fdisk, and then press ENTER.
3. View step 2.
For a Windows 95 Startup disk:
1. At a command prompt, type fdisk, and then press ENTER.
2. View step 2.
If your hard disk is larger than 512 MB, you receive the following message:
Your computer has a disk larger than 512 MB. This version of Windows includes improved support for large disks, resulting in more efficient use of disk space on large drives, and allowing disks over 2 GB to be formatted as a single drive.

IMPORTANT: If you enable large disk support and create any new drives on this disk, you will not be able to access the new drive(s) using other operating systems, including some versions of Windows 95 and Windows NT, as well as earlier versions of Windows and MS-DOS. In addition, disk utilities that were not designated explicitly for the FAT32 file system will not be able to work with this disk. If you need to access this disk with other operating systems or older disk utilities, do not enable large drive support.

Do you wish to enable large disk support?
If you want to use the FAT32 file system, press Y and then press ENTER. If you want to use the FAT16 file system, press N, and then press ENTER.For additional information about the FAT32 and FAT16 file systems, click the article numbers below to view the articles in the Microsoft Knowledge Base:
118335 Maximum Partition Size Using FAT16 File System
154997 Description of the FAT32 File System

After you press ENTER, the following Fdisk Options menu is displayed:

1. Create DOS partition or Logical DOS Drive
2. Set active partition
3. Delete partition or Logical DOS Drive
4. Display partition information
5. Change current fixed disk drive

Note that option 5 is available only if you have two physical hard disks in the computer.

Press 1 to select the Create DOS partition or Logical DOS Drive menu option, and then press ENTER.
Press 1 to select the Create Primary DOS Partition menu option, and then press ENTER.
After you press ENTER, you receive the following message:
Do you wish to use the maximum available size for primary DOS partition?
After you receive this message, use one of the following methods, depending on the file system that you selected.
For a FAT32 File System
1. If you press Y for the FAT32 file system (in step 2) and you want all of the space on the hard disk to be assigned to drive C, press Y, and then press ENTER.
2. Press ESC, and then press ESC to quit the Fdisk tool and return to a command prompt.
3. View step 7.
For a FAT16 File System
If you press N for the FAT16 file system (in step 2), you can accept the default 2 GB size for the partition size, or you can customize the size of the partition.

To accept the default partition size:
1. If you want the first 2 GB on the hard disk to be assigned to drive C, press Y, and then press ENTER.
2. Press ESC to return to the Options menu, and then view step d in the following "To customize the partition size" section.
To customize the partition size:
1. If you want to customize the size of the partitions (drive letters) on the hard disk, press N, and then press ENTER.
2. A dialog box is displayed in which you can type the size that you want for the primary partition in MB or percent of disk space. Note that for computers that are running either Windows 98 or Windows Me, Microsoft recommends that you make the primary partition at least 500 MB in size. Type the size of the partition that you want to create, and then press ENTER.
3. Press ESC to return to the Options menu.
4. To assign drive letters to the additional space on the hard disk, press 1, and then press ENTER.
5. Press 2 to select the Create Extended DOS Partition menu option, and then press ENTER.
6. You receive a dialog box that is displays the maximum space that is available for the extended partition. You can adjust the size of the partition or use the default size. Note that the default maximum space is recommended, but you can divide the space between multiple drive letters. Type the amount of space that you want, press ENTER, and then press ESC.
7. The Create Logical DOS Drive(s) in the Extended DOS Partition menu is displayed. This is the menu that you can use to assign the remaining hard disk space to the additional drive letters. Type the amount of space that you want to assign to the next drive letter in the Enter logical drive size in Mbytes or percent of disk space (%) box, and then press ENTER.
8. A table that lists the drive letter that you created and the amount of space on that drive is displayed. If there is free space on the hard disk, it is displayed near the bottom of the table. Repeat steps e through g until you receive the following message:
  All available space in the Extended DOS Partition is assigned to local drives.
9. After you receive this message, press ESC to return to the Options menu.
10. To activate the partition from which you plan to boot (usually drive C), press 2 to select the Set active partition menu option, and then press ENTER.
11. When you receive the following message, press 1, and then press ENTER:
  Enter the number of the partition you want to make active.
12. Press ESC, and then press ESC to quit the Fdisk tool and return to a command prompt, and then view the following "How to Format a Hard Disk" section in this article.

How to Format a Hard Disk

After you create the partitions, you must format the partitions:

Restart your computer with the Startup disk in the floppy disk drive.

NOTE: If you are using a Windows 95 Startup disk, a command prompt is displayed and you can skip to step 2. If you are using a Windows 98, Windows 98 Second Edition, or Windows Me Startup disk, select the Start computer without CD-ROM support menu option when the Windows 98 Startup menu is displayed.
When a command prompt is displayed, type format c: /s, and then press ENTER. This command transfers the system files and should only be used when you format drive C (or your "active" drive). For all other partitions, type format drive: (where drive is the letter of the partition that you want to format).

NOTE: If you receive a "Bad command" or "Bad file name" error message, you may need to extract the Format.com tool to your boot disk. To do this, type the following command at a command prompt, and then press ENTER:
extract ebd.cab format.com
After the Format.com tool is extracted to your boot disk, type format c: /s t a command prompt to format your active partition, or type format drive: if you want to format a partition that is not your active partition.
When you successfully run the Format.com tool, you receive the following message:
WARNING, ALL DATA ON NON-REMOVABLE DISK DRIVE C: WILL BE LOST!
Proceed with Format?
Press Y, and then press ENTER to format drive C.
After the format procedure is finished, you receive the following message:
Volume label (11 characters, ENTER for none)?
NOTE: This is an optional feature that you can use to type a name for the drive. You can either type an 11-character name for the drive, or you can leave it blank by pressing ENTER.

For information about how to repartition the extended partition and logical drives, view the "How to Repartition and Format the Extended Partition and Logical Drives of a Hard Disk" section in this article.

How to Repartition and Format a Slave Hard Disk

How to Repartition a Slave Hard Disk

If you want to add a second hard disk (slave drive) to your computer, you need to make sure that the jumpers on both the master (original) and slave (new drive) are set according to the manufacturer's instructions first so that your computer can detect the hard disks. Verify that your hardware is installed correctly, and then follow these steps:

Click Start, point to Run, and then type command (Note that the cmd command only works on Windows 2000-based computers).
At a command prompt, type fdisk, and then press ENTER. The following menu is displayed:
```
1. Create DOS partition or Logical DOS Drive
2. Set active partition
3. Delete partition or Logical DOS Drive
4. Display partition information
5. Change current fixed disk drive
```
Note that menu option 5 is available only if you have two physical hard disks on your computer.
Press 5, and then press ENTER. When you do this, the selection changes from the physical disk 1 (master) to the physical disk 2 (slave).
Press 1 to select the Create DOS partition or Logical DOS Drive menu option, press ENTER, press 2 to select the Create Extended DOS Partition menu option, and then press ENTER. When you make your slave drive an extended MS-DOS partition, your drive letters does not change. For example, if the first drive contains partition C and partition D, your slave drive becomes D unless you set the slave drive as an extended partition. If you skip this step and just create another primary MS-DOS partition for the slave drive, the new drive becomes drive D and what used to be drive D, changes to drive E.
You can partition the slave drive to make other logical drives just as you did with the original master drive. If your computer cannot detect the new drive, you may need to add the following line to your Config.sys file, where drive is a letter that is greater than the last drive letter on the computer (including the CD-ROM drive):
lastdrive=drive
After you finish using the Fdisk tool, format the new partitions so that you can use them. After you press ESC to quit the Fdisk tool, restart your computer to start Windows.

How to Format a Slave Hard Disk

To format your new partition or partitions, use one of the following methods, depending on your file system. For a FAT16 file system:

Double-click My Computer, right-click the partition that you just created, click Format, click Full, and then click Start.
After the format procedure is complete, click OK to close the dialog box.

For a FAT32 file system:

Click Start, point to Programs, point to Accessories, point to System Tools, click Drive Converter (FAT32), and then click Next.
In the Drives box, click the drive that you want to convert to the FAT32 file system.
Click Next, and then click OK.
Click Next, click Next, and then click Next again.
When the conversion procedure is finished, click Finish.

NOTE: Do not use the /s switch that you used when you set up drive C. All you need to do is to format the drive or drives so that you can use them (for example, if you created two new drive letters, you need to format both drives).

For information about how to repartition the extended partition and logical drives, view the following "How to Repartition and Format the Extended Partition and Logical Drives of a Hard Disk" section in this article.

How to Repartition and Format the Extended Partition and Logical Drives of a Hard Disk

Use the steps in this section to resize or combine your extended partition and logical drives. Make sure that you have a reliable backup of any important data that you have on your extended partition and logical drives before you proceed. If you want to combine your entire hard disk in one partition, use the steps in the "How to Partition and Format a Master Hard Disk" section in this article.

How to Repartition the Extended Partition and the Logical Drives

NOTE: When you use this method, two or more partitions are left on your hard disk, a primary partition (usually drive C) and an extended partition. Even if you use the FAT32 file system, there is an 8-GB partition limitation unless you obtain a BIOS upgrade that fully supports interrupt 13 extensions. For additional information about why there is an 8-GB limit, click the article number below to view the article in the Microsoft Knowledge Base:

153550 Hard Disk Limited to 8-GB Partition

If you have a hard disk that is larger than 8 GB and you are not using a disk overlay program or disk management software, you need to partition and format the space that is remaining after you create each 8-GB partition:

Place the Startup disk in your floppy disk drive, restart your computer, and then use one of the following methods, depending on your operating system. For a Windows 98, Windows 98 Second Edition, or Windows Me Startup disk:
1. When the Microsoft Windows 98 Startup menu is displayed, select the Start computer without CD-ROM support menu option, and then press ENTER.
2. At a command prompt, type fdisk, and then press ENTER.
3. Go to step 2.
For a Windows 95 Startup disk:
1. At a command prompt, type fdisk, and then press ENTER.
2. Go to step 2.
If your hard disk is larger than 512 MB, you receive the following message:
Your computer has a disk larger than 512 MB. This version of Windows includes improved support for large disks, resulting in more efficient use of disk space on large drives, and allowing disks over 2 GB to be formatted as a single drive.

IMPORTANT: If you enable large disk support and create any new drives on this disk, you will not be able to access the new drive(s) using other operating systems, including some versions of Windows 95 and Windows NT, as well as earlier versions of Windows and MS-DOS. In addition, disk utilities that were not designated explicitly for the FAT32 file system will not be able to work with this disk. If you need to access this disk with other operating systems or older disk utilities, do not enable large drive support.

Do you wish to enable large disk support (Y/N)?
If you want to use the FAT32 file system, press Y and then press ENTER. If you want to use the FAT16 file system, press N, and then press ENTER.For additional information about the FAT32 and FAT16 file systems, click the article numbers below to view the articles in the Microsoft Knowledge Base:
118335 Maximum Partition Size Using FAT16 File System
154997 Description of the FAT32 File System

After you press ENTER, the following Fdisk Options menu is displayed:

1. Create DOS partition or Logical DOS Drive
2. Set active partition
3. Delete partition or Logical DOS Drive
4. Display partition information
5. Change current fixed disk drive 
  (this option is only available if you 
   have two physical hard disks in the computer)

Press 3, and then press ENTER. The following menu is displayed:

1. Delete Primary DOS Partition
2. Delete Extended DOS Partition
3. Delete Logical DOS Drive(s) in the Extended DOS Partition
4. Delete Non-DOS Partition

Press 3, and then press ENTER.

The Delete Logical DOS Drive(s) in the Extended DOS Partition screen is displayed with a chart that describes the attributes of your hard disk, as shown in the following example.

Drv	Volume Label	Mbytes	System	Usage
D:	(User Defined)	2047	FAT16	100%
E:	(User Defined)	2047	FAT16	100%
F:	(User Defined)	2047	FAT16	100%
G:	(User Defined)	2047	FAT16	100%
H:	(User Defined)	2047	FAT32	17%
I:	(User Defined)	1498	UNKNOWN	13%

Total Extended DOS Partition size is XXX Mbytes (1 MByte = 1048576 bytes).

WARNING! Data in a deleted Logical DOS Drive will be lost.

What drive do you want to delete? Type the letter for the drive that you want to delete, and then press ENTER.

When you are prompted to type the volume label for the drive, type the volume label if the drive has a volume label.

NOTE: You must type the exact label or press ENTER if there is no volume label. If you type an incorrect label name, you receive the following message:
Volume label does not match.
Enter Volume Label?
If you type the correct volume label, you receive the following message:
Are you sure (Y/N)?
The default answer to this message is N. You must press Y, and then press ENTER to delete the drive. The words "Drive deleted" are displayed in the chart next to the drive letter that you deleted.
Repeat steps 3 through 7 until you have deleted all of the drives that you want to delete. When you are finished, press ESC. If you remove all of the logical drives, you receive a "No logical drives defined" message and a chart of drive letters that you changed or deleted. Press ESC to continue.

NOTE: If you want to resize the logical drive or drives by making them larger or smaller, do this now. If you want to remove the extended partition, view step 11.
Press 1 to select the Create DOS partition or Logical DOS Drive menu option from the Fdisk Options menu, press 3 to select the Create Logical DOS Drive(s) in the Extended DOS Partition menu option from the Create DOS Partition or Logical DOS Drive menu, and then press ENTER. When you do this, you receive a "Verifying drive integrity" message with a percentage-complete counter.

NOTE: When you use this step, the extended partition is not deleted, only the logical drive or drives in the extended partition are deleted. You do not need to remove the extended partition to resize the logical drives. For example, if you have one logical drive in the extended partition and you want to make two logical drives, delete the logical drive and create two logical drives in the extended partition first. Note that you are still limited to the total space in the extended partition.
After the drive verification procedure is finished, you receive the following message:
Total Extended DOS Partition size is XXX Mbytes (1 MByte = 1048576 bytes)

Maximum space available for logical drive is XXX Mbytes (X%)

Enter logical drive size in Mbytes or percent of disk space (%).
The "maximum Mbytes available" is the default size, however, you can change the number if you type the number for the partition size that you want to create, and then pressing ENTER. Press ESC, press ESC to quit the Fdisk tool and return to a command prompt, and then view step 11.
If you want to remove the extended MS-DOS partition, press ESC to return to the Fdisk Options menu. Press 3 to select the Delete DOS Partition or Logical DOS Drive menu option, press ENTER, press 2 to select the Delete Extended DOS Partition menu option, and then press ENTER.
The screen shows the current fixed disk drive and information about it. The extended partition is listed in the Type column. For example:
```
Partition  Status  Type  Volume  Label         Mbytes  System   Usage
C:         1 A     PRI   DOS     (your label)  1200    FAT16    50%
2                  EXT   DOS     (your label)  1200    UNKNOWN  50%

Total disk space is 2400 Mbytes (1 Mbyte = 1048576 bytes)
```
You also receive the following warning message:
WARNING! Data in the deleted Extended DOS Partition will be lost.

Do you wish to continue (Y/N)?
Press Y, and then press ENTER to delete the partition. You receive the following message:
Extended DOS Partition deleted
Press ESC to continue
NOTE: If you try to delete your extended MS-DOS partition before you remove all of the logical drives, you receive the following error message:
Cannot delete Extended DOS Partition while logical drives exist.
If you receive this error message, repeat steps 3 through 6, and then follow steps 9 and 10 to delete the extended MS-DOS partition.

The Fdisk Options menu is displayed. If you leave disk space unpartitioned on your hard disk, Windows may not display the full size of your hard disk, only the amount of space that is available.

IMPORTANT: After you change the Fdisk options or delete partitions, the data that was on the partition is deleted and cannot be retrieved. Be very sure that you understand this procedure before you attempt to follow it. If you want to start with a clean configuration or if you want to redo your current configuration, back up everything that is important to you before you use the Fdisk tool.
If you want to use the unpartitioned space on your hard disk, you must format the drives. When you successfully run the Format.com utility, you receive the following message:
WARNING, ALL DATA ON NON-REMOVABLE DISK DRIVE X: WILL BE LOST!
Proceed with Format (Y/N)?
Press Y, and then press ENTER to format the drive.
After the format procedure is finished, you receive the following message:
Volume label (11 characters, ENTER for none)?
NOTE: This is an optional feature that you can use to type a name for the hard disk. You can either type an 11-character name for the drive, or leave it blank and press ENTER.

Frequently Asked Questions

Question: Why does the Fdisk tool only partition 2 GB of space at a time?

Answer: If you can only partition 2 GB of space at a time, you may have pressed N when you were prompted to enable large disk support, or you may be running a version of Windows that does not support FAT32. If you are running Windows 95 or earlier on your computer, you must create multiple partitions to use the full drive size.

NOTE: If you are running a retail version of Windows 95 you cannot upgrade to Windows 95 OSR2.For additional information about your version of Windows 95 or Windows 98, click the article number below to view the article in the Microsoft Knowledge Base:
158238 How to Determine the Version of Windows 95/98/Me in Use
Question: I have software that is larger than the 504-MB limit. Should I use it?

Answer: To ensure compatibility, check with the software manufacturer before you use any disk management software.
Question: I have software or utilities that support drives larger than the 504MB limit, should I use it?

Answer: Yes, you can copy the Windows 95 or Windows 98 installation from your old hard disk to a new hard disk. For additional information about how to duplicate your Windows 95 or Windows 98 installation on a new hard disk, click the article number below to view the article in the Microsoft Knowledge Base:
166172 Duplicating Windows 95/98 Installation to a New Hard Disk
Note that you cannot use the method described in this article to copy Windows 95 or Windows 98 installations to multiple computers. Microsoft only supports the standard Setup procedure as described in the Windows 95 and Windows 98 product documentation.