Lost “My Computer” in Start Menu

I have lost all capability to see “My Computer” and its associated drive structure in both the Desktop and Start Menu. I am using Windows XP Pro SP2 and the new Start Menu config (2 column). I tried using Windows Explorer to see the drives but all I see in the Folder pane is My Documents and Desktop. Also, in the Start Menu – Properties – Customized – Advanced menu I do not see a My Computer in the menu. I have tried gpedit.msc, Display Properties, TweakUI XP, X-Setup, and Advanced System Optimizer as well as a Windows XP Pro SP2 repair from CD to fix this problem. System Restore and Last Known Good Config don’t do a thing. I think it has to do with something(s) in the System Registry, but don’t know where to start looking…