Back Up Registry

If you're planning on making numerous changes to different areas of the registry in Windows Vista, backing up each individual registry key could quickly become frustrating.
Luckily, there's an easy way to export the entire Windows Registry.
This way, after backing up the entire registry, you can make changes to several registry keys and then be able to restore them all at once if need be.
Follow these easy steps to back up the entire Windows Vista Registry.
Note: The steps below require working with the Windows Registry. Making changes other than the ones described below could cause serious problems.
Difficulty: Easy
Time Required: Backing up the entire Windows Vista Registry usually takes less than 10 minutes
Here's How:
1. Click on Start.
2. In the search box, type regedit and hit your Enter key. The Registry Editor program will open.
3. Navigate to the very top of the registry key branches until you reach Computer.
4. Highlight Computer by clicking on it once.
5. From the Registry Editor menu, choose File and then choose Export....
6. In the Export Registry File window that appears, choose a location to save the file to.
Note: I usually recommend choosing your desktop or the C:\ drive. Both are easy to access if you run into problems later and need to use the file to restore data.
7. Locate the File name: text field and enter a name for the backup file.
Note: This name is for you to remember what the exported registry file is for. Since you're backing up the entire Windows Vista Registry, I would recommend calling this file Registry Backup or something like that.
8. Click the Save button.
A Registration File with an REG file extension will be created in the location you chose in Step 6 and with the file name you chose in Step 7. Continuing the example from the last step, the file would be named Registry Backup.reg.
9. You can now make as many changes to any area of the registry that you want.
10. If after making your registry changes, you realize that they did not give you the results you were looking for, you can simply restore the entire Windows Vista registry back to the point at which you backed it up