Either way, you were proactive and backed up the registry just in case something happened.
Follow these steps to restore previously backed up registry data to the Windows 7 Registry:
Note: The steps below require working with the Windows Registry. Making changes other than the ones described below could cause serious problems.
Locate the Registration File you exported before making your changes to the Windows 7 Registry.
Having trouble locating the file? Assuming you actually did make an export from the registry, look for a file ending in the REG file extension. Check your Desktop, in your Documents folder, and in the root folder of your C: drive.
It might also help to know that a REG file icon looks like a broken Rubik's cube in front of a piece of paper.
Double-click on the REG file to open it.
Note: Depending on how you have Windows 7 configured, you could see a User Account Control dialog box appear next. You'll need to confirm that you want to open Registry Editor, which you never actually see because it only runs in the background as part of the registry restore process.
Next you'll be prompted with a message in a Registry Editor window:
Adding information can unintentionally change or delete values and cause components to stop working correctly. If you do not trust the source of this information in [REG file location], do not add it to the registry. Are you sure you want to continue?
Important: This isn't a message to be taken lightly. If you're importing a REG file that you did not export or one you downloaded from a source you can't trust, be aware that you could cause considerable damage to Windows 7, depending on the registry keys being changed.
Click the Yes button.
Assuming the registry key(s) import was successful, you should receive the following message in a Registry Editor window:
The keys and values contained in [REG file location] have been successfully added to the registry.
Click the OK button in this window.
The registry keys contained in the REG file have now been restored to the Windows 7 Registry. If you know where the registry keys were located, you can open Registry Editor and verify that the changes were made as you expected.
Restart your computer.
Depending on the changes that were made restoring the registry keys, you may need to restart to see the changes take effect in Windows 7 or in your programs.