The error you get is a generic "access denied".
Try the following:
1) Install Classic Shell and ignore the errors (if you haven't already)
2) Open an admin command prompt (for example from the Win+X menu)
3) Type "regsvr32 c:\windows\syswow64\StartMenuHelper32.dll"
4) If you don't get any errors, type "regsvr32 StartMenuHelper64.dll"
5) If you get errors, I'd like you to run some tests trying to determine the exact operation that is failing:
a. Download the program Process Monitor from here:
http://technet.microsoft.com/en-us/sysi ... 96645.aspx b. Run it as administrator
c. Set a filter for "Process Name is regsvr32.exe"
d. From the command prompt type the command again (either "regsvr32 c:\windows\syswow64\StartMenuHelper32.dll" or "regsvr32 StartMenuHelper64.dll", whichever failed)
e. When you get the error, press the blue magnifying glass in the toolbar to stop the logging
f. Look for any "access denied" errors. Report what registry key was being accessed. You can also save the log in a PML file, zip it, and attach it here