http://www.microsoft.com/windowsxp/using/setup/learnmore/tips/movetaskbar.mspx

TonyE, Thank you for your answer. However, it doesn't help - MY BAD. I see that I failed to mention that I want to hide the Windows Taskbar on the left hand side of the screen - WHILE I AM LOGGED ON THE INTERNET WITH FIREFOX. Thank you again. I notice that sometimes the Window's task bar is there on the left at the start of a session. BUT, IT DOESN'T STAY FOR LONG.

Do you want to keep that Taskbar at the left side of the screen?

If that bar isn't locked then you can move it to the bottom of the screen.

If you want to keep it at the left then look for the autohide setting in the option of the Taskbar (right-click context menu)

You can move the taskbar to top, bottom, left or right edge of your monitor as the TonyE and cor-el suggest, when it is not locked (right-click on a blank spot in the task bar; a check mark next to "Lock the taskbar" indicates it is locked; toggle locked to unlocked by clicking on "Lock the taskbar").

You can have the taskbar automatically hide, by right-clicking the "Start" button, click "Properties", click the Taskbar tab, place a check mark (click) "Auto-hide the taskbar" (note, no need to unlock taskbar to change this option). When you move the cursor to the position of the taskbar (left, right, top, bottom of the monitor) the taskbar will slide/pop into view; when you move the cursor away, the taskbar will again auto-hide. The option is all or none, there is no option to hide it only when surfing the internet. You can turn the taskbar back on (to always display) by un-checking the "Auto-hide the taskbar" option.

See: http://www.coolnerds.com/XP/Taskbar/xpTaskbar.htm (see the "Setting Taskbar Options" section for auto-hide and other options)