The failing fan could be letting the PC overheat. Most PCs will either lockup or slow down as the heat rises. You may have to fix that issue first.
My system is really working very slowly. It starts to get slower from the moment I turn it on. Then, within about a half hour, it crawls to a stop. My PC has been making a lot of noise for quite a while now but I haven't gotten around to doing anything about it. I don't know if that is related but it seems very possible. Does it sound like my system is just dying? If it's a virus, AVG can't detect it. Is there anything I can try to do about this problem or do I need to bring it to a professional? (I have Windows ME and DSL.)