Reinstalling your operating system really isn't a big deal, and that would solve the problem.

The essential thing is to have an external hard drive you can use to save all your data, and other stuff, such as installation files for any programs you need that you haven't got on CDs, or are readily downloadable, and so forth.

It's a bit of a drag, and it ties you up for a few hours, but it means you've got a cleen computer that's running the way it should. And once you've done it it's easy enough to do over again every few months, if you are organised enough to keep the re-installation stuff up-to-date. I always make a firmn resolution to do that, and always fall down on it...

If you are using Windows it's pretty certain you are going to have to do it some time, so now's maybe as good a time as any to get your head round it.

Oh yes, it's obvious, but... Make sure to unhitch that external hard disc before you start reinstalling. Then when the machinehas done its pieces, you just reload the stuff you want reloaded on to the main computer.

If the problem is on the extenal disc, the thing to do is temporarily store any stuff that's on it which you want to keep, and reformat the disc.