Windows and its Virtual Desktop Manager (Powertoys) or deskman.exe

[Reverend]

Make sure you are downloading the XP version.
You can get it direct from M$ here

Select "Complete" option when installing.

When you have installed it, Right click on the taskbar, click toolbars, and then click "Desktop Manager." This will put the Virtual Desktop Manager in the taskbar.(view attachment below).

To view all 4 desktops click the green button,to view individual desktops click the relevant numbered button.

You can uninstall via Add/Remove. Look for "Virtual Desktop Manager Powertoy For XP. (close the manager first before running uninstall,Right click on the taskbar, click toolbars, and then uncheck "Desktop Manager.)

Hope that helps.