Every now and then my PC will just freeze regardless of what I'm doing. Last night I left it on downloading something then this morning I woke up to find it froze at 5am. When I try to turn it off and on again I get a repetitive high pitch/low pitch whirring coming from one of the fans and I get no display output at all. If I leave it for about 20mins it'll start working again. Because of this I've figured that something is probably overheating, but I've no idea what. Can anyone recommend a software that can give me component specific temperatures? CPU, RAM, GPU and HDDs at least. I want to narrow down what needs replacing. I've opened her up and had a good clean, all fans are working fine. Any ideas?