If, when you click on Control Panel or System Restore or such, you get a blank white window, it could possibly be a script problem, and you may have to re-register some dll's. Try to re-register the following dll files in System32 folder. If you don't find the files, then try to extract then from your Vista setup DVD and copy them to System32 folder first.
vbscript.dll
jscript.dll
mshtml.dll
Emsa Register Dll Tool and Register/ Unregister OCX/DLL Utility
are two utilities, with which you can achieve the same on the fly.
Regarding the WU issue, check out if any of the troubleshooting steps given
here help you.