How To BackUp and Restore the Registry

Manually Copying Files

You can back up the registry by manually copying the registry files from their storage location in the file system to another location. However, to make use of these files in the event of registry failure, you need to be able to start the computer by using an operating system that can read both the file system of the backup media and of the partition in which the non-working operating system is installed. Because you cannot copy files while they are open and in use, and the files that constitute the registry are always open and in use while the operating system is running, you cannot simply copy them as you would a typical file. To copy these files, you must shutdown the operating system and use another installed operating system or utility that can access and read the file system.

To back up the registry by manually copying files, copy all files in Systemroot\System32\Config to removable media, a network share, or a compatible partition. Be sure to note the actual path to these files, because Systemroot resolves differently when your computer is running a different operating system.

To restore the registry by manually copying files, copy the backed up registry files from their backup location to their original location (the location indicated by Systemroot\System32\Config when the associated operating system was running). This overwrites all registry settings with those in the backed up registry files. Restart the computer by using the repaired operating system.

Regedit.exe and Reg.exe

The registry editor Regedit.exe and the command-line tool Reg.exe allow you to back up and restore individual subkeys, keys, or whole subtrees by saving parts of your registry as files on your computer, removable media, or network shares.

Reg.exe can only be used to modify local registries, but Regedit.exe can be used to modify both local and remote registries. If a problem prevents users from logging in but does not stop the system from starting up, you might be able to connect to that system remotely from another computer by using Regedit.exe.