From eScan Wiki
Q. How to take the backup of windows registry?
A. Open the Windows Registry (you can refer to [[Escan/english/eScan-FAQ96|FAQ - How to start the windows registry editor?)
- Browse to the part of the registry where you will make changes,
- Right click on the key and select Export,
- Type the file name and select the destination folder and click “Save”
- Backup file with extension “.reg” is saved
- When you need to undo changes, just click on backuped reg file and original values will be written back into registry.