Tom accidentally moved his taskbar to the right side of the screen. He asked the Answer Line forum how to move it back.
To move the taskbar to another edge of the screen, or to return it to its original position at the bottom, first right-click an empty space on the taskbar and uncheck Lock the taskbar. (There's a good chance that if you're in Tom's position, you don't have to do this. The taskbar is probably already unlocked.)
Once the taskbar is unlocked, click on an empty space there and drag. That's it.
If you want to avoid this happening again, right-click the taskbar and check Lock the taskbar.
Read the original forum discussion.