Error Message: Your Computer Already Has an Operating System Installed, Which Cannot Be Upgraded by This Version of Setup

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When you try to upgrade your Microsoft Windows 95-based computer to Windows 98, you may receive the following error message:
Warning SU0168
Your computer already has an operating system installed, which cannot be upgraded by this version of Setup. Please obtain the Windows 98 Upgrade.
This issue can also occur if you try to upgrade with a full version. Before troubleshooting, ensure CD-ROM installation is Upgrade version.
This issue can occur for either of the following reasons:
  • An incorrect version of the Setupx.dll file is currently loaded into memory.
  • Your installation media (CD-ROM or floppy disk) may be damaged.
To resolve this issue:
  1. Click Start, click Shutdown, click Restart the computer in MS-DOS mode, and then click OK.
  2. At the command prompt, type the following commands, pressing ENTER after each command:
    cd windows\system
    ren setupx.dll setupx.ol1
    ren setupx.w95 setupx.ol2
    NOTE: If the Setupx.w95 file is missing, extract a new copy of the Setupx.dll file from the current operating system's installation media to the Windows\System folder.For additional information about how to extract files, click the article number below to view the article in the Microsoft Knowledge Base:
    129605 How to Extract Original Compressed Windows Files
  3. Type exit, and then press ENTER.
  4. Click Start, click Run, type cdromdriveletter:\win98\setup.exe, and then click OK.

Damaged Installation Media

If you suspect that your installation media is damaged, contact the Microsoft Order Desk at 800-360-7561 Monday-Friday, 5:00 A.M. to 7:00 P.M. PST.

Article ID: 225252 - Last Review: 12/05/2015 13:52:10 - Revision: 3.0

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