Hi,
Please check for the existence of the following files at the %windir%\system32 directory:
Srrstr.dll
Srclient.dll
Srcore.dll
Rstrui.exe
After that, try steps below to re-register core files:
1. You will only be able to re-register the file srcore.dll.
2. Launch an elevated command prompt
3. From the command prompt type the following command:
Regsvr32 srcore.dll
4. Insert the Windows Vista disk and type the following command:
sfc /scannow
Hope it helps.
Tim Quan - MSFT