Mr Fixit Strikes Again

I'm known in the family as the computer expert. I can qualify this comment by saying that I'm not an expert, I just know a bit more than other members of the family. The latest episode has been related to a speed issue with our family workhorse computer. This computer is where I do my blogging, video capturing, iTunes storing etc. and my wife does her research and watches TV programmes on it and so on. You name it, this is our general main computer in the house for it. So it's switched on most of the time. We're not known for compulsive cleaning in our house, dusting is not something we do generally and neither is ironing. So anyway, we've been experiencing 24 hours of snail pace computing - literally it taking five minutes after clicking on something for the computer to do anything. It was showing less signs of life than a Zombie. We were even at the stage where we were preparing to buy another computer. Reasoning dictated to me a course of action whereupon I disconnected all cables and opened up the computer box. The hot weather we have been experiencing lately has exacerbated the problem. My thinking was based on a pop-up notification from a processor temperature monitor program that said something to the  effect that the processor was getting too hot and the fan speed was raised while reducing the throughput of work that the processor did. All this mumbo jumbo told me was that the brain in our PC was getting overheated. I cleaned out the box not so long ago, as I experienced similar problems when processing 60 minutes of video from our camcorder over a period of about 7 hours! To cut to the nub, I took the PC shell outside and used my wife's hairdryer on cold air setting to blow all the dust from the motherboard and the fans on the power supply and GPU and what I could reach of the CPU fan. Funnily enough that seems to have cured the problem and we can once more use our workhorse. Thank goodness because all of our links, email, documents, music, photos and video are on this machine and getting it all back on to a new computer would have been a nightmare. I know we should backup frequently but who does?