How many times have you pressed F2 to rename a file and missed extensions? This is very common, and windows should have this feature that prevents users from changing the extension type. Well, one way is never to show your file extensions, making it a lot better when you rename and still preserve the file type or Time time for another utility.
TheEnd is another small utility by the same guy who wrote Create Shortcut There, and it deselects the Extension automatically when you press f2 or rename.
This utility doesn’t need installation, but it keeps running in the background. You can have it on startup and save a lot of hassles when you rename it. Download TheEnd