HOW TO: Disable the Upgrade Basic Disks to Dynamic Disks Functionality in Windows 2000 (317587)

SUMMARY

This step-by-step article describes how to use Registry Editor to disable the functionality that allows you to upgrade basic disks to dynamic disks on a Windows 2000-based computer. You can use the procedure that is described in this article on all user accounts, including the administrator account. back to the top

Reasons to Disable the Upgrade Basic Disks to Dynamic Disks Functionality

A dynamic disk is a physical disk that contains dynamic volumes that you create by using Disk Management. Dynamic disks do not use traditional partition tables like primary and extended partitions (logical drives); therefore, dynamic disks cannot be accessed by MS-DOS, Microsoft Windows 95, Microsoft Windows 98, Microsoft Windows Millennium Edition (Me) or Microsoft Windows NT operating systems.

When you convert a basic disk to a dynamic disk, the partition layout on the disk changes and the dynamic disk database is created. These changes provide you with increased flexibility to manage the volume in Windows 2000 and Microsoft Windows XP Professional. However, these changes are not easily reversed, and the structure of dynamic disks is not compatible with some operating systems. Therefore, you must consider the following issues before you convert basic disks to dynamic disks:

Do not convert a basic disk to a dynamic disk if it contains multiple copies of Windows XP Professional or Windows 2000. Even though these operating systems support dynamic disks, they require certain registry entries to start from dynamic disks. If the operating systems are installed on the same disk and you use one of the operating systems to convert the disk to a dynamic disk, the registry of the other operating system becomes out-of-date because the drivers that are required to start the operating system from a dynamic disk are not loaded. Therefore, you can no longer start the other operating system.

You can use dynamic disks with Windows XP Professional and Windows 2000 in a multiple-boot configuration if you install each operating system to a different disk. For example, install Windows 2000 on disk A and Windows XP Professional on disk B. Use Windows 2000 to convert disk A to a dynamic disk, and then use Windows XP Professional to convert disk B to a dynamic disk. By using this method, you ensure that the registries are updated for each operating system.
You can access dynamic disks only from computers that are running Windows 2000, Windows XP Professional, or Windows XP 64-Bit Edition. You cannot access dynamic disks from computers that are running MS-DOS, Windows 95, Windows 98, Windows Me, Windows NT 4.0 or earlier, or Windows XP Home Edition. This restriction also means that you cannot start any of these operating systems if you convert the disk that contains the system volume to a dynamic disk.

To avoid this restriction, use two hard disks. Install the other operating system on the first disk, which contains the system volume, and then install Windows on the second disk. If you use this method, you can convert the disk that is running Windows to a dynamic disk and still start the other operating system on the basic disk. However, this method prevents the other operating system from accessing the dynamic disk or any of its volumes and data. Therefore, in computers that start multiple operating systems, you must use caution when you convert basic disks to dynamic disks.

The partition style that is used on the dynamic disk can also restrict access to dynamic disks. The following list describes the different partition styles and their limitations:
- Dynamic master boot record (MBR) disks: Only computers that are running Windows 2000, Windows XP Professional, or Windows XP 64-Bit Edition can access dynamic MBR disks.
- Dynamic GUID partition table (GPT) disks (where GUID is the abbreviation for globally unique identifier): Only Itanium-based computers that are running Windows XP 64-Bit Edition can access dynamic GPT disks.
NOTE: Volumes on dynamic MBR and GPT disks are available across a network to computers that are running MS-DOS, Windows 95, Windows 98, Windows Me, Windows NT 4.0 or earlier, or Windows XP.
Do not convert a basic disk to a dynamic disk if the disk contains unknown partitions that are created by other operating systems. Windows converts unknown partitions to dynamic partitions, which makes them unreadable to other operating systems.
Do not convert a disk to a dynamic disk if it contains an original equipment manufacturer (OEM) partition that is not located at the beginning of the disk. (In Disk Management, an OEM partition typically is displayed as an EISA configuration partition.) When you convert a basic disk to a dynamic disk, Windows preserves the OEM partition only if this partition is the first partition on the disk. If this partition is not the first partition, the partition is deleted when the disk is converted to a dynamic disk.
You can extend dynamic volumes that do not retain their partition entries in the partition table. The following list describes the volumes that retain their entries in the partition table and cannot be extended:
- The system volume and boot volume of the operating system that you used to convert the disk to dynamic.
- Any basic volume that was present on the disk when you converted the disk from a basic disk to a dynamic disk by using the version of Disk Management that is included with Windows 2000.
- Simple volumes on which you run the DiskPart retain command. The retain command adds a partition entry to the partition table. However, after you use this command, you can no longer extend the volume.
To add more space to the system volume or boot volume on a dynamic disk, you must back up all of the data on the disk, repartition and reformat the disk, reinstall Windows, convert the basic disks to dynamic disks, and then restore the data from backup.

The following volumes do not have partition entries and can be extended:
- Simple volumes and spanned volumes that are created from unallocated space on a dynamic disk.
- A basic volume that is not the system volume or the boot volume, but it is on a disk that you converted from a basic disk to dynamic disk by using Windows 2000.
In addition, you cannot extend striped volumes. Although striped volumes do not have entries in the partition table, you cannot extend this volume in Windows 2000. To add more space to a striped volume, back up the data, delete the volume, recreate the volume by using Windows 2000, and then restore the data.
Disk Management does not offer FAT as a formatting option for dynamic volumes because the NTFS file system is the preferred file system for dynamic volumes. If you want to format a dynamic volume by using FAT, use My Computer, Microsoft Windows Explorer, or the format command.
The DiskPart command that is used in the Recovery Console can damage your partition table if the disk has been upgraded to a dynamic disk. Always use Disk Management to modify the structure of dynamic disks.
Windows 2000 does not support reverting your boot disk from a dynamic disk to a basic disk.
Dynamic disks are not supported on the following hardware:
- The Institute of Electrical and Electronics Engineers (IEEE) 1394 serial bus
- The Universal Serial Bus (USB)
- Removable disks
- Disks in laptop computers or laptop docking stations

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