I was doing my usual - 5 internet sites - 2 poker sites - spreadsheet. Suddenly my task bar disappeared. A: Why? B: How do I get it back - short of reboot? Thanks in advance for your help.

Lol try reboot

Or press control+alt+del to get into taskmanager and go to processes tab

End all processes called explorer.exe, and your taskbar will reappear (if it doesn't reboot)