Configure the Windows XP logon screen saver

If you ever work in a computer lab or an Internet café where systems regularly sit idle waiting for someone to log on, you know that Windows XP will display the Logon dialog box or the Welcome screen for 10 minutes before running the default logon screensaver, which is the Windows XP logo floating on a black background. You can change the default logon screensaver to something different, such as the OpenGL 3D Pipes screen saver, and you can even shorten the amount of time that Windows XP waits before activating the screensaver. Here’s how to do both:
Launch the Registry Editor (Regedit.exe).
Go to HK_USERS\.DEFAULT\Control Panel\Desktop.
Locate and double-click the SCRNSAVE.EXE string value.
When you see the Edit String dialog box, type the name of the screensaver you want in the Value Data text box and click OK.
Locate and double-click the ScreenSaveTimeOut string value and change the value from 600 seconds to another number, such as 120 for two minutes.
Close the Registry Editor and restart Windows XP.
After the system restarts and you see the Logon or Welcome screen, leave the system untouched for two minutes to see your new screensaver in action.
Note: This tip applies to both Windows XP Home and Windows XP Professional. As always, remember that editing the registry is risky, so be sure to back up your computer before undertaking any registry changes.