Always it is better to perform a backup of any essential data
before manipulating it. In order to save your registry settings or
restore registry settings from a backup, use the registry backup and
restore tool:
To perform a backup:
Select create new backup
option then click the next button, you will be prompted with a
window that asks for a backup name (this tool will offer a default
name you could change it), then click next button to complete the
backup process.
To perform a Restore from backup:
Select
restore an older backup option then click the next button, Select
the file you wish to restore from the list of registry backup files
you have previously saved, and then click the next button. You will
be prompted with a window that asks you for what part of backed up
files you want to restore. Select files you want to restore then hit
the next button.
Note: you must reboot in order for the newly
restored registry data to be used.
