The start menu is everything in Windows. It can be quite a problem for the users if it stops working all of a sudden. It becomes almost impossible to do anything on your PC and may cause a lot of delays in your work.
Solution 1 : Registry Editor
(works for : XP, Vista, 7)
press the Windows key and [R], type “regedit” and press [Enter].
Browse to :
HKEY_CURRENT_USER\ Software\Classes\Local Settings\Software\Microsoft\Windows\ CurrentVersion\TrayNotify
delete both IconStreams and PastIconsStream values