The Microsoft Registry Editor (regedit.exe) enables you to view, search for, and change settings in your system registry, which contains information about how your computer runs. Although you can use Registry Editor to inspect and modify the registry, doing so is not recommended, as making incorrect changes can damage your system.
You might need to use Registry Editor, with assistance from a technical support professional, in order to adjust certain system settings.

Regedit.exe is automatically installed during setup and is stored in same folder as is Windows.

To start Regedit.exe
1.Click Start, and then click Run.
2.Type Regedit, and then click OK.