You receive an "Other Operating System found" error message when you try to upgrade to Windows XP

When you try to upgrade your Microsoft Windows 95-based, Microsoft Windows 98-based, or Microsoft Windows ME-based computer to Microsoft Windows XP, you may receive an error message that is similar to the following:

This problem can occur if the following conditions are true:

• You previously installed Windows XP
• You uninstalled Windows XP
• Folders from the original Windows XP installation are still on your computer

To resolve this problem, perform the following procedures in order:

Verify hardware compatibility

Verify that any external devices that are connected to your computer are compatible with Windows XP. Remove any external devices if those devices are not compatible with Windows XP. For more information about device compatibility with Windows XP, visit the following Microsoft Web site:

Remove unknown devices

Remove unknown devices that are listed in Device Manager.

For additional information about how to troubleshoot unknown devices listed in Device Manager, click the following article number to view the article in the Microsoft Knowledge Base:

Delete previous system installation files

1. Disable any antivirus software that is running on your computer. For information about how to disable antivirus software, contact the manufacturer of the software.
2. Create a temporary storage folder for any files from the original system installation that are still on your hard disk. To do this, follow these steps:
   1. Click Start, click Run, type drive: where drive: is the letter of the hard disk where Windows is installed, and then click OK.
   2. On the File menu, point to New, click Folder, type XPOldFiles, and then press ENTER.
3. Verify that a folder named Windows is on the hard disk. Then search for any other folders that may contain system files. Typically, these folders have names such as:
   • $WIN_NT$, Windows.000, or something similar
   • anything with 20 or more random characters; for example, 9470bb12e8a4f3447657236478e41c5
   If you find any folders other than the Windows system folder that contain system files, move these folders to the XPOldFiles folder. To do this, right-click the folder that you want to move, click Cut, right-click the XPOldFiles folder, and then click Paste.
4. Search for the system files that are listed in this step on your hard disk. Then move the files to the XPOldFiles folder. To do this, follow these steps:
   1. Click Start, point to Find, and then click Files or Folders.
   2. In the Named box, type file name where file name is one of the following names:
      • Boot.ini
      • Bootsect.dos
      • NTLDR
      • ntdetect.com
      • Pagefile.sys;Hiberfil.sys
   3. In the Look in box, click My Computer.
   4. Click Find Now.
   Search for each name in the list. If any files appear in the list of found files, right-click the file, click Cut, right-click the XPOldFiles folder, and then click Paste.
5. Search for system files and folders from the previous installation that are inside the Windows system folder. Then move these files to the XPOldFiles folder. To do this, follow these steps:
   1. Click Start, click Run, type %Systemroot%, and then click OK.
   2. Search for folders that have the following names:
      • LastGood
      • ServicePackFiles
      • any name that starts with "$NTUninstall"
      If you locate these folders, right-click the folder, click Cut, right-click the XPOldFiles folder, and then click Paste.
   3. Search for a file named Ntoskrnl.exe. If you locate this file, right-click the file, click Cut, right-click the XPOldFiles folder, and then click Paste.

Run upgrade again

Try to run the Windows upgrade again. If the upgrade is successful, delete the XPOldFiles folder from your hard disk.