Registry Editor is an advanced tool for viewing and changing settings in your system registry, which contains information about how your computer runs. Almost the entire settings are stored in the registry. For example, your conrol panel applets like your mouse settings etc are stored there.This is just an example, there are much more data stored in the registry.

Although Registry Editor enables you to inspect and modify the registry, it's advisable to use Registry Editor only if the GUI does not provide the option you're looking for. Making incorrect changes in the registry can break your system. It's highly advisable to backup the registry before editing any portion of it.

Although there are a nuber of ways to back it up the following is the best:

* Click Start, and then click Run.

* In the Open box, type regedit, and then click OK

* Locate and then click the key that contains the value that you want to edit

* On the File menu, click Export.

* In the Save in box, select a location where you want to save the Registration Entries (.reg)

* In the File name box, type a file name, and then click Save.

Note: you can either backup a single key or the whole registry