How to Perform a Clean Boot in Windows 95 (243039)

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The following steps can help you to determine if the problem that you are experiencing is due to the real-mode configuration of your computer. This could include drivers that are loaded from your Config.sys and Autoexec.bat files.

1. Restart your computer. When the Starting Windows 95 dialog box is displayed, press F8, and then choose Step-By-Step Confirmation from the Startup menu.
2. When you are prompted, load the following items (if you are prompted to load any other items, press N):
   • Dblspace driver.
   • Himem.sys.
   • Ifshlp.sys.
   • Dblbuff.sys.
   • Load the Windows 95 graphical user interface (GUI), choosing to load all Windows drivers.

NOTE: Windows 95 does not require the Config.sys and Autoexec.bat files, but some tools installed on the computer may require them. You should never rename the Config.sys and Autoexec.bat files until you perform a successful interactive boot to verify that they are not needed.

If the clean boot of your real-mode configuration eliminates the issue, isolate the conflict with a terminate-and-stay-resident (TSR) or real-mode device driver using the Step-By-Step Confirmation function.

Load Windows 95 by booting to a command prompt and starting Windows 95 by typing win, holding down the SHIFT key for the duration of the boot. This prevents any programs from loading automatically at startup.

If the issue is resolved by preventing programs from loading at startup, investigate the following possible sources.

The Winstart.bat File

The Winstart.bat file is used to load TSRs that are required for Windows-based programs and are not needed in MS-DOS sessions.

For additional information the Winstart.bat file, click the article number below to view the article in the Microsoft Knowledge Base:

The Startup Group

If the issue is resolved by bypassing the Startup group, remove each of the programs from the Startup group individually to isolate the program that is causing the problem.

The Run Key in the Registry

WARNING: If you use Registry Editor incorrectly, you may cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that you can solve problems that result from using Registry Editor incorrectly. Use Registry Editor at your own risk.


You can prevent programs from loading by removing the program's string from the following registry keys: Programs may also be loading from the following registry key:

The Win.ini File

The "load=" and "run=" lines in the [Windows] section of the file can start programs automatically. See the following section for more information.

Test Windows Configuration Files

To test the Windows configuration files, use the following steps:

1. Boot to a command prompt.
2. Rename the Win.ini file by typing the following command:

   ren c:\windows\win.ini *.bak

3. Start Windows 95 by typing win. If this procedure corrects the problem, ensure that the "load=" and "run=" lines in the [Windows] section of the Win.ini file are either blank or preceded with a semicolon (;) to prevent the items from loading.
4. Rename the System.ini file by typing the following command:

   ren c:\windows\system.ini *.bak

5. Windows 95 requires a System.ini file to load the GUI. Replace the original file by typing the following command:

   copy c:\windows\system.cb c:\windows\system.ini

   NOTE: Starting Windows 95 with the System.cb file does not load a driver for the mouse. Edit the new System.ini file, adding the following lines:

   [386Enh]
   mouse=*vmouse, msmouse.vxd
   
   [boot]
   drivers=mmsystem.dll
   mouse.drv=mouse.drv

6. Start Windows 95 by typing win at the command prompt. If replacing the original System.ini file with the System.cb file corrects the issue, the problem most likely resides with either the [boot] or [386Enh] sections of the original System.ini file. Restore the original file to troubleshoot it.
7. To isolate the cause of the problem, place a semicolon (;) at the beginning of a line to prevent the item from loading.

For additional information about the System.ini file and its default entries, click the article number below to view the article in the Microsoft Knowledge Base:

Protected-Mode Device Drivers

Safe mode disables all protected-mode device drivers for Windows 95. You can conduct testing for incompatible components and resource conflicts by disabling the protected-mode device drivers in Device Manager.

Removing Protected-Mode Device Drivers to Isolate Conflicts

1. Click Start, point to Settings, click Control Panel, and then double-click System.
2. On the Device Manager tab, click View Devices By Type.
3. Disable each of the protected-mode device drivers. For example:
   1. Double-click the Floppy Disk Controllers branch to expand it.
   2. Click Standard Floppy Disk Controller, and then click Properties.
   3. On the General tab, click to clear the Original Configuration (Current) check box, and then click OK.NOTE: If you have enabled hardware profiles, there is a check box for each of the configurations. Clear the check box for the hardware profile you are troubleshooting.
      
      
   4. Repeat steps A-C for each device in Device Manager.
4. Click Close, and then restart the computer.

If you resolve the issue by disabling the protected-mode drivers in Device Manager, you may have a hardware conflict or a driver may be incompatible with your hardware. For additional information about troubleshooting resource conflicts in Windows 95, click the article number below to view the article in the Microsoft Knowledge Base: If you determine that a Windows 95 protected-mode device driver is incompatible with your hardware, contact the hardware manufacturer to determine the availability of new drivers.

Changing the Video Driver to a Standard VGA Display Driver

NOTE: If you followed the directions in the "Removing Protected-Mode Drivers to Isolate Conflicts" section of this article, you changed the display driver to VGA and you can skip to the next section. Disabling the display adapter sets your video to the VGA driver.

Safe mode starts Windows 95 with the VGA display driver. To determine if the issue you are experiencing is related to your video driver, change to the VGA driver for testing purposes.

NOTE: To ensure a safe return to your previous configuration, use the following steps:

1. Back up the System.ini file.
2. Note the current desktop area (resolution) and color palette.
3. Record the name of your current video adapter.

To change to the VGA display driver, follow these steps:

1. Start Windows 95 in Safe mode.
2. Click Start, point to Settings, click Control Panel, and then double-click Display.
3. On the Settings tab, click Change Display Type.
4. In the Adapter Type area, click Change.
5. Click Show All Devices.
6. In the Manufacturers box, click (Standard Display Types). In the Models box, click Standard Display Adapter (VGA), and then click OK.
7. Click OK or Close until you return to Control Panel.
8. Restart your computer.

If you determine that your video driver is incompatible with Windows 95, contact the hardware manufacturer to determine the availability of new drivers.

Registry Damage

When you start Windows 95 in Safe mode the registry is read minimally. Damage to the registry may not be evident when running in Safe mode; you may need to replace the existing registry (System.dat) with a backup to determine if the issue is caused by a damaged registry. To troubleshoot a damaged registry, use the following steps:

1. Boot to a command prompt.
2. Remove the file attributes from the backup of the registry by typing the following command:

   c:\windows\command\attrib -h -s -r c:\system.1st

3. Remove the file attributes from the current registry by typing the following command:

   c:\windows\command\attrib -h -s -r c:\windows\system.dat

4. Rename the registry by typing the following command:

   ren c:\windows\system.dat *.dax

5. Copy the backup file to the current registry by typing the following command:

   copy c:\system.1st c:\windows\system.dat

6. Restart your computer.

NOTE: The System.1st file is a backup of the registry created during the final stage of Windows 95 Setup. Therefore, the "Running Windows 95 for the first time" banner is displayed and Windows 95 finalizes settings as if it is being installed.

If replacing the System.dat file with the System.1st file resolves the issue, the problem may be related to registry damage. Programs and device drivers added after you installed Windows 95 may require reinstallation to update the new registry.

If the issue is not resolved, restore the original registry using the following steps:

1. Restart the computer to a command prompt.
2. Type the following commands, pressing ENTER after each command:

   c:\windows\command\attrib -s -h -r c:\windows\system.dat
   copy c:\windows\system.dax c:\windows\system.dat

   NOTE: Overwrite the existing System.dat file if you are prompted to do so.
   
   
3. Restart the computer.

The Windows 95 CD-ROM includes tools for backing up your system files as well as the registry. For additional information about these tools, click the article numbers below to view the articles in the Microsoft Knowledge Base:

What to Do if the Problem Persists

If the troubleshooting steps outlined in this article do not resolve the issue, the issue may be related to one or more of the following items:

• Faulty hardware.
• The computer needs a special machine switch for Himem.sys.
• The CMOS settings may need to be changed (such as disabling shadow RAM).
• The system BIOS may require an upgrade to be compatible with Windows 95.
• A virus may be present.
• An upgrade of a previous Windows installation may have been unsuccessful.

To determine if Windows 95 is compatible with your current system configuration, you may need to install Windows 95 to a clean directory.

If you have enough free disk space, install Windows 95 to an empty folder (such as a Win95 folder). For information about how to do so, see the following article in the Microsoft Knowledge Base: For additional information about troubleshooting Windows 95 startup problems and error messages, click the article number below to view the article in the Microsoft Knowledge Base: If this resolves the issue, your previous installation may have included components incompatible with Windows 95.