This step involves making changes in the registry. Always back up your registry before making any changes.
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.