How to Troubleshoot Registry Errors

ID: Q131431

The information in this article applies to:
  • Microsoft Windows 95
IMPORTANT: This article contains information about editing the registry. Before you edit the registry, you should first make a backup copy of the registry files (System.dat and User.dat). Both are hidden files in the Windows folder.

SYMPTOMS

When you start Windows 95, you may receive one of the following error messages:

  • There is not enough memory to load the registry.


  • Windows has encountered an error accessing the system registry. You should restore the registry now and restart the computer.

    If you ignore this error and shut down your system, you may lose data.

    Restoring the registry replaces the faulty registry with a known good backup copy. However, this backup copy may not contain all the information recently added to your system.

    NOTE: If you click the Restore From Backup And Restart button, you receive the error message again as Windows 95 restarts.



CAUSE

These error messages may occur if the registry is damaged.


RESOLUTION

WARNING: Using Registry Editor incorrectly can cause serious problems that may require you to reinstall Windows 95. Microsoft cannot guarantee that problems resulting from the incorrect use of Registry Editor can be solved. Use Registry Editor at your own risk.

NOTE: For information about how to edit the registry, view the Changing Keys And Values online Help topic in Registry Editor (Regedit.exe). Note that you should make a backup copy of the registry files (System.dat and User.dat) before you edit the registry.

Perform the steps outlined in each method below (as needed) to restore a damaged registry.

Using Real-Mode Registry Editor

Use Registry Editor in real mode to export, then import, the registry file. To do so, follow these steps:
  1. Restart the computer. When you see the "Starting Windows 95" message, press the F8 key, then choose "Safe mode command prompt only" from the Startup menu.


  2. Type the following line to export the registry
    regedit /l:<path1> /e <path2>system.txt
    where <path1> is the path to the System.dat file and <path2> is the path to the destination file. For example, if Windows 95 is installed in the Windows folder on drive C, type the following line:
    regedit /l:c:\windows\system.dat /e c:\system.txt


  3. Type the following lines, pressing ENTER after each line:
    cd\windows
    attrib -s -h -r system.dat


  4. Type the following line to rename the current registry file:
    ren system.dat system.old


  5. Type the following line to import the System.dat portion of the registry
    regedit /l:<path1> /c <path2>system.txt
    where <path1> is the path to the System.dat file and <path2> is the path containing the file to import. For example, if Windows 95 is installed in the Windows folder on drive C and you want to import the System.txt file from the root folder of drive C, type:
    regedit /l:c:\windows\system.dat /c c:\system.txt
    NOTE: If an "Unable to open registry" or "Error accessing the registry" error message is displayed when you attempt to import the System.dat portion of the registry, please see the following article in the Microsoft Knowledge Base for more information about the error message:
    Q132064 Regedit May Not Be Able to Import Registry with Large Keys


  6. Restart Windows 95 normally.


If the error continues to occur, follow these steps:
  1. Restart the computer. When you see the "Starting Windows 95" message, press the F8 key, and then choose "Safe mode command prompt only" from the Startup menu.


  2. Type the following line to export the User.dat portion of the registry
    regedit /r:<path1> /e <path2>user.txt
    where <path1> is the path to the User.dat file and <path2> is the path to the destination file. For example, if Windows 95 is installed in the Windows folder on drive C, type the following line:
    regedit /r:c:\windows\user.dat /e c:\user.txt


  3. Type the following lines, pressing ENTER after each line:
    cd\windows
    attrib -s -h -r user.dat


  4. Type the following line to rename the User.dat file:
    ren user.dat user.old


  5. Type the following line to import the User.dat portion of the registry
    regedit /r:<path1> /c <path2>user.txt
    where <path1> is the path to the User.dat file and <path2> is the path containing the file to import. For example, if Windows 95 is installed in the Windows folder on drive C and you want to import the User.txt file from the root folder of drive C, type:
    regedit /r:c:\windows\user.dat /c c:\user.txt
    NOTE: If an "Unable to open registry" or "Error accessing the registry" error message is displayed when you attempt to import the User.dat portion of the registry, please see the following article in the Microsoft Knowledge Base:
    Q132064 Regedit May Not Be Able to Import Registry with Large Keys


  6. Restart Windows 95 normally.


For additional information about using Registry Editor in real mode, please see the following article in the Microsoft Knowledge Base:
Q131352 Using Registry Editor in Real Mode
If the error continues to occur after you follow the steps in this section, please see the next section.

Using System.da0

Restore the registry to its state when you last successfully started Windows 95. To do so, follow these steps:
  1. Restart the computer. When you see the "Starting Windows 95" message, press the F8 key, then choose "Safe mode command prompt only" from the Startup menu.


  2. Type the following command to move to the Windows folder
    cd \<windows>
    where <windows> is the Windows 95 folder. For example, if Windows 95 is installed in the Windows folder, type the following line:
    cd \windows


  3. Type the following line:
    attrib -s -h -r system.dat


  4. Type the following line:
    ren system.dat system.bad


  5. Restart your computer. Windows 95 uses the System.da0 file when it cannot find the System.dat file. If this file works, Windows 95 renames it to System.dat.


If the error continues to occur after you follow the steps in this section, please see the next section.

Using System.1st

Restore the registry to its state when you first started Windows 95 successfully. To do so, follow these steps:
  1. Restart the computer. When you see the "Starting Windows 95" message, press the F8 key, then choose "Safe mode command prompt only" from the Startup menu.


  2. Type the following command to move to the Windows folder
    cd \<windows>
    where <windows> is the Windows 95 folder. For example, if Windows 95 is installed in the Windows folder, type the following line:
    cd \windows


  3. Type the following line:
    attrib -s -h -r system.dat


  4. Type the following line:
    ren system.dat system.xxx


  5. Type the following line:
    cd \


  6. Type the following line:
    attrib -s -h -r system.1st


  7. Type the following line
    copy system.1st c:\<windows>\system.dat
    where <windows> is your Windows 95 folder.


  8. Type the following line:
    attrib +s +h +r system.1st


  9. Restart your computer.


If the error continues to occur after you follow the steps in this section, please see the next section.

NOTE: You may find that your TrueType fonts are missing from the Fonts folder or in programs after you follow the above steps. If this is the case, use the resolution listed in the following article in the Microsoft Knowledge Base:
Q133732 Missing TrueType Fonts in Fonts Folder or Programs

Reinstalling Windows 95

Re-create the registry files by reinstalling Windows 95.

To do this, perform the following steps.

NOTE: If you cannot access the CD-ROM drive from the command prompt, consult the CD-ROM drive's documentation or manufacturer for assistance with loading the real-mode drivers for the CD-ROM drive.
  1. Restart the computer. When you see the "Starting Windows 95" message, press the F8 key, then choose Command Prompt Only from the Startup menu.


  2. Type the following line and then press ENTER to remove all user profiles:
    ren c:\windows\profiles c:\windows\oldprofiles


  3. Rename the existing registry files by typing the following lines. Press ENTER after each line:
    cd \windows
    attrib -s -h -r system.dat
    ren system.dat system.xxx
    attrib -s -h -r user.dat
    ren user.dat user.xxx
    attrib -s -h -r system.da0
    ren system.da0 system.yyy
    attrib -s -h -r user.da0
    ren user.da0 user.yyy
    cd \
    attrib -s -h -r system.1st
    ren system.1st system.zzz


  4. Run Windows 95 Setup.


Note that you may have to reinstall programs, especially those that write to the registry, after you restore the backup or use System.1st to replace the registry.

Additional query words: corrupt tshoot repair troubleshooting

Keywords : kbenv kberrmsg kbtshoot win95
Version : WINDOWS:95
Platform : WINDOWS
Issue type : kbinfo


Last Reviewed: January 20, 2000
© 2000 Microsoft Corporation. All rights reserved. Terms of Use.