Just spent half an hour searching for this so i thought I'd share for other bods with similar probs. I had installed a new drive and consequently changed the original installation path. Just tried Start>Run>'sfc /scannow' and it gave me error messages complaining about wrong path/CD etc. So I amended a couple of things in regedit: Change letter to new drive letter. [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion] "SourcePath"="Z:\" [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Setup] "Installation Sources"=Z:\ "SourcePath"="Z:\" Thats it!