In a WSUS environment, Windows XP clients may obtain automatic updates from the Windows Update Web site instead of from the WSUS server. The %SystemRoot%\windowsupdate.log file may contain errors.

This behavior will occur if registry entries are corrupted, which can happen if you upgraded the client from SUS (Software Update Services) to WSUS.

To resolve this issue on the client:

1. Open a CMD.EXE window.

2. Type the following commands, pressing Enter after each line:

net stop wuauserv                              REG DELETE "HKLM\Software\Microsoft\Windows\CurrentVersion\WindowsUpdate\Auto Update" /V LastWaitTimeout /F                              REG DELETE "HKLM\Software\Microsoft\Windows\CurrentVersion\WindowsUpdate\Auto Update" /V DetectionStartTime /F                              REG DELETE "HKLM\Software\Microsoft\Windows\CurrentVersion\WindowsUpdate\Auto Update" /V NextDetectionTime /F                              REG ADD "HKLM\Software\Microsoft\Windows\CurrentVersion\WindowsUpdate\Auto Update" /V AUState /T REG_DWORD /F /D 2                              REG ADD "HKLM\Software\Microsoft\Windows\CurrentVersion\WindowsUpdate\Auto Update" /V ConfigVer /T REG_DWORD /F /D 1                              REG ADD "HKLM\Software\Microsoft\Windows\CurrentVersion\WindowsUpdate\Auto Update" /V SusServerVersion /T REG_DWORD /F /D 1
3. Shutdown and restart the Windows XP client.