Changes made to the Windows Registry happen immediately, and no backup is automatically made. Making improper changes can cause damage to your installation of Windows and can potentially result in data loss or a complete failure of Windows. Do not edit the Windows Registry unless you are confident about doing so.

Backing up your Registry is easy. Simply open the Registry (click Start -> Run – or Windows Key + R, type regedit and click OK), then select File -> Export from the “File” menu. You can export a copy of your Registry to any folder on any hard drive in your system. Exporting a copy to the desktop is usually easiest.