How to clean up the Add or Remove Programs tool utility in Control Panel

When uninstalling a program, you normally click on the Remove button on the Add or Remove Programs tool utility. It will ask you for confirmation to uninstall the program and once the program has been uninstalled, the program name entry will be removed from the list. However, when the Remove button does not work, and the program stays on the list (instead of asking for the confirmation), you can remove the entry from the list by deleting the registry entry on the Registry Editor. Extreme care should be taken when working on registry entries.

How to remove the program entry on the Add/Remove Programs tool:
1. Click Start -> Run.
2. Type regedit.
3. Click OK. The Registry Editor will open.
4. Go to: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall.
5. Find the key you want to delete (example: Mozilla Firefox 12 x86).
6. Save a backup of the registry key: On the Registry Menu, Export the registry key. Import this key later if necessary.
7. Delete the selected registry key and its values. WARNING!! Do not delete the entire Uninstall key.
8. Close the Registry Editor.
9. Check to make sure the program entry has been removed: Click Start.
10. Control Panel -> Add or Remove Programs.