How To Back Up Your Computer Registry
Backing up your computer registry, or making a copy of your registry, is a great way to ensure that you can return your computer to a previous status. This process is especially helpful when you are planning to make changes to your hard drive, or install new software.
Open Start menu and select Run. Type regedit in the dialog box that appears. Click OK.
In Registry Editor, go to the File menu and select Export. Under the export range, select All.
Save as a *.reg file with an appropriate file name (example: Registry Files).
To restore your registry, go to the File menu and select Import.
Select the proper file and click OK.