Open regedit and goto:
Code:
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer
And make sure that there no DWORD value exists as following:
NoStartMenuMorePrograms
NoCommonGroups
If they exist, then delete them.
Its just my guess, may be it'll work for u.