1. Press Windows + R keys.
2. Type Regedit, and then click OK.
3. When the Registry Editor opens, the window has two panes.
4. Right-click the registry key you wish to back up on the left pane, and then select Export.
5. At the bottom of the Export Registry File window that opens, select the desired Export Range.  
   • All (*Recommended)
   • Selected Branch (to backup just highlighted key) 
6. Enter a filename for the file, and then click Save.
7. The exported registry key will be saved as a .reg file.

Section 2: How to restore a backed-up registry key

1. Locate the backed-up registry key, it will have a .reg extension.
2. Double-click the file.
3. At the Are you sure you want to add the information prompt, select Yes.
4. An additional window will appear to confirm the information in the registry backup, click OK.