Simple pointer: Defragger doesn't work after reg cleaning?

I'm sure it was Kodo who taught ME this a year or so ago, and it's worth passing on to those who might have missed it, cuz it happened to me today again:

If you've run a reg cleaner, and then suddenly when you try to defrag your hard drive(s), your Windows native defragger won't respond (won't analyze; won't defrag; won't even blink!), ...

The most promising, easiest solution is to reinstall the defragger. Your reg cleaner probably killed the path to it in your registry.

Open your Windows folder, find the "inf" folder in there, find the dfrg.inf file (or look for a filename that's close to that), right click it, and choose Install.

Now try your defragger again. You shouldn't even have to reboot. It should work.