The following handy shortcuts can be used in Windows XP on a PC with the Windows key on the keyboard.
Windows B - Move to back Windows D - Show/Hide desktop Windows E - Windows Explorer Windows F - Find Windows L - Lock workstation Windows M - Minimize all windows Windows R - Run Windows U - Utility Manager
To use them, hold down the windows key and press the appropriate letter then release both keys. Note that some may not be available to those people operating in a heavily secured environment. All bar Windows L and Windows U also work on Windows 2000.
Additional shortcuts can be created using a free piece of software called WinKey. Although sadly discontinued and no longer supported by its original developers, it may still be available from free software download sites.