The following describes how to back up and restore the Windows 95 registry files.
To back up and restore the Windows 95 registry files, use one of the following methods:

To back up your registry files, follow these steps:

1. Restart your computer. Press the F8 key when you see the "Starting Windows 95" message, and then choose Safe Mode Command Prompt Only from the Startup menu.
2. At the command prompt type the following lines, pressing ENTER after each line:
   1. cd windows
   2. attrib -r -h -s system.dat
   3. attrib -r -h -s user.dat
   4. copy system.dat *.bu
   5. copy user.dat *.bu

   NOTE: This procedure assumes you do not have any files named System.bu or User.bu. If you do have files by this name, such as a backup of the System.ini file, select a file name extension that is not currently in use.

3. Restart your computer.

To restore your registry files, follow these steps:

1. Restart your computer. Press the F8 key when you see the "Starting Windows 95" message, and then choose Safe Mode Command Prompt Only from the Startup menu.
2. Type the following lines at the command prompt, pressing ENTER after each line:
   1. cd windows
   2. attrib -r -h -s system.dat
   3. attrib -r -h -s system.da0
   4. attrib -r -h -s user.dat
   5. attrib -r -h -s user.da0
   6. ren system.dat system.daa
   7. ren system.da0 system.da1
   8. ren user.dat user.daa
   9. ren user.da0 user.da1
   10. copy system.bu system.dat
   11. copy user.bu user.dat

   NOTE: This procedure assumes you do not have any files named System.daa, System.da1, User.daa, or User.da1. If you do have files by this name, select a file name extension that is not currently in use.

3. Restart your computer.

Notes: You may want to back up more than one version of the registry in case the registry becomes damaged but the damage is not detected until later. If you want to do this, when you are following the steps above, replace the .bu extension with .bu1, .bu2, and so on.
If you have more than one hard disk or a network drive is available, you may want to copy the backup files to the other drive so the backup files do not reside in the same location as the original registry files.

You can use the Windows 95 Emergency Recovery Utility to create a backup of your system configuration and registry files and restore these files in case a problem should occur. For information about using the Windows 95 Emergency Recovery Utility, see the following article in the Microsoft Knowledge Base: 139437 Windows 95 Emergency Recovery Utility Additional Information

Windows 95 stores information about the hardware and software in your computer in the System.dat and User.dat files. The System.dat and User.dat files should be treated as a pair. You should back them up together as a pair and restore them together as a pair. These files are hidden, read- only files.
Note that if you are using user profiles, you should also backup the User.dat files located in the following folders

C:\Windows\Profiles\