I just had MY taskbar disappear...no idea why. So hit the 'WIN' key..(or, as John says, ctrl/esc will work)..then went to control panel->taskbar&start menu-> and checked 'auto hide'.....when I exited, the taskbar APPEARED when I moused over it...so I went back to control panel and UNchecked 'auto-hide'...and LO...it was back again. Gotta trick it!