Weird problem with startbar disappearing

Hi,
I've got a weird fault develop with my pc. I haven't changed anything (I dont think) the startbar isnt there! I tried right-clickign it refreshing the desktop changing some options in the startbar control panel ---> nothing. it is like deadspace, no menus on rc notihing. Any ideas on how to get it back?
I would prefer not to make a new user.

mad_pc_man

Does this happen only when you are using photoshop?

nope, all the time, it appears briefly at startup (0.5/1s) then disappears

*bump*

Hit WinKey+R to bring up the Run box, and type regsvr32 /i shell32... you'll need to reboot after re-registering the *.dll. You may also want to scan for viruses and malware / spyware. If the above command doesn't work for you, bring up the Run box again and type sfc /scannow.