Quick Notes on Windows XP Shortcut Keys using the Windows Key. These are used when only the desktop is showing.
[Windows Key] + [Q] = Quick-Switch Users
[Windows Key] + [E] = Start Windows Explorer
[Windows Key] + [R] = Show the Run dialog box
[Windows Key] + [F] = Open the Find window
[Windows Key] + [L] = Lock the computer / show the login screen
[Windows Key] + [U] = Starts the Utility Manager