Incorrectly editing the registry can severely damage your system. Editing and managing the registry is for advanced users only. The instructions below are offered only as a reminder, not as a tutorial for novice users.
You should always back up (export a copy of) the registry before you make any changes to it.
To backup the registry
Click Start > Run. The Run dialog box appears.
In the Open box, type regedit, then press ENTER. The Registry Editor appears.
Do one of the following:
To backup the entire registry, click My Computer.
To backup a specific group of keys or a specific key, click the folder or key.
On the main menu, click File > Export. The Export Registry File dialog box appears.
Specify a name and location for the file, then click Save. The export process begins.
If you are exporting the entire registry, it can take a few minutes, and the file size can be up to 100 MB or more. If you are exporting just one key, the file size is approximately 1 KB.
After you edit the registry, if you are experiencing problems caused by editing the registry, you can import the backed up file:
On the main menu, click File > Import. The Import Registry File dialog box appears.
Click the .reg file to import, then click Open. The import process begins. If you are importing the entire registry, it can take a few minutes.
Creating a .reg File
Manually Creating Registry Keys