I realize this post is very old, but I just recently encountered this issue and also came up with a much easier possible solution than what has been previously posted: I deleted any/all occurrences of desktop.ini in the following directories:

Code:
C:\ProgramData\Microsoft\Windows\Start Menu
C:\ProgramData\Microsoft\Windows\Start Menu Places
After deleting (3) occurrences of destop.ini, my Start Menu was immediately no longer grayed-out. HTH someone!