Go to Start » Run and type: regedit
On the left side, click to highlight My Computer at the top.
Go up to File » Export
Make sure in that window there is a tick next to "All" under Export Branch.
Leave the "Save As Type" as "Registration Files".
Under "Filename" put RegBackup.
Choose to save it to C:\
Click save and then go to File » Exit.
Or you can download and use ERUNT which is an excellent free tool that allows you to to take a snapshot (backup) of your registry before making changes and restore it when needed.
Click on the link below:
Scroll down to #128 and click "Desktop and Screensaver Tabs" in the right column. Go to File, choose "Save page as" All Files and save desktoptab.reg to your desktop. Double-click on that file and choose "Yes" to merge it into the registry when prompted. Once you get a successful message delete the file and reboot.
Edited by boopme, 29 May 2009 - 11:57 AM.