ARCHIVED: How do I uninstall Windows 98 or 98SE?

This document applies to computers with Windows 95 that were upgraded to Windows 98 or 98SE without reformatting the hard disk. It does not apply to computers whose hard disks were formatted before installing Windows 98 or 98SE. The Windows 98 upgrade utility can roll back an installation to a "previous version" (i.e., Windows 95) if you so choose. That's what "uninstalling" Windows 98 or 98SE means in this document.

If you have installed Windows 98 or 98SE on your computer and you wish to uninstall it, consider the following before proceeding:

• You cannot uninstall if the hard disk that Windows 98 or 98SE resides on has been compressed with any program, either before or after the Windows 98 or 98SE installation.
• You cannot uninstall if you have converted your hard disk to the FAT32 file system.
• You cannot uninstall if you are missing any of the following files:

    winundo.dat
    winundo.ini
    uninstal.exe
    suhdlog.dat

• While it may still be possible, it is not advisable to uninstall Windows 98 or 98SE if you have changed the size or number of partitions on the drive. When Windows 98 or 98SE uninstalls, it changes the partitioning of the disk back to the way it was before it was installed, which can cause data loss. This could result in a failure of the uninstall process and the loss of all data on the drive, not just the operating system.
• Boot sector viruses can cause a failure in the uninstall process. This is because a virus can prevent Windows from restoring the original partition information.

If none of the above situations apply to you, you can start the uninstall of Windows 98 or 98SE. If you are able to start Windows, follow these instructions to begin the uninstall process:

1. From the Start menu, select Settings, then Control Panel.
2. Double-click the Add/Remove Programs icon, then click Uninstall Windows 98. Click the Add/Remove button and then select Yes.
3. When you are asked if you want to check the disk for errors, click Yes. This will start ScanDisk.
4. When ScanDisk finishes, Windows will ask you if you wish to continue. Click Yes.
5. Follow the instructions on the screen to continue with the uninstall.

If you cannot get into Windows when you turn your computer on, you may uninstall from the command prompt. To uninstall Windows 98 or 98SE from the command prompt, follow these instructions:

1. Turn your computer off. Wait 15 seconds and turn it back on.
2. Hold down the Ctrl key until the Windows Startup screen appears.
3. At this point, most people should choose Command Prompt Only. However, if you are running any real-mode Novell NetWare clients (VLM or NetX) from MS-DOS, you will need to select Safe Mode Command Prompt.
4. Type each of the following two lines, pressing Enter after each line:

     cd \windows\command
     uninstal.exe

5. When you are prompted to continue, press y. This process may take several minutes.

Note: If you are unable to uninstall Windows 98 or 98SE due to any of the situations listed in the first section above, then the required files to complete this procedure will not be available to you.

This information was adapted from article 186102 in the Microsoft knowledge base.