Recently I uninstalled dozens of applications, which were no longer needed, from my Windows 7 Professional SP-1 32-bit desktop, and used Registry First Aid to delete erroneous registry entries afterwards. Since then, the context menu for two CD/DVD drives, one internal SATA REV drive, and an external USB REV drive is missing the 'Format...' option. Using Disc Manager, there is no longer an option to format those drives. An external USB thumb drive still has the format option on right click. I have tried multiple approaches to fixing this, including ejecting and re-connecting USB devices and running SFC. Other Windows operating systems on the same desktop still have the format option for those drives. Eventually I restored a disc image which was made before the changes which I mentioned, and now the format option is again appearing. If I knew which registry key(s) create that format option, I'd prefer to restore the disc to its recent state (without the obsolete applications) and just fix the context menu for drives with removable storage.