This is a simple task but you would be surprised the questions I am asked. I am going to show you how to backup Windows 7 registry; super easy.
Backup entire Windows 7 registry
Click on your start menu, and type regedit. Hit enter.
Go up to the file menu, and click on “Export.”
Choose a location, choose your filename, and under the Export Range leave “All” selected. Then hit “Save.” You can re-import this at anytime by either double clicking on the *.reg file or doing an import from the file menu within regedit.