Credit crunch computing part 1

Over the last few weeks, my XP-equipped desktop machine (the core elements of which I've had for nearly 5 years, although the rule of Will Hay's mortarboard applies) has been freezing and slowing. As I've been doing much the same, I've been inclined to forgive it. However, in the last few days, it was getting so painful that I was considering a clean reinstall of XP, never something to be undertaken lightly, even with my rigorous backup procedure in place. It didn't occur to me until yesterday that the heatsink might be clogged up with dust. After all, I last flushed it out a few months ago at most. When the brainwave landed on my bonce, I checked the CPU temperature and, sure as eggs is eggs, it was nudging 60 deg C, which while not meltdown is far from ideal. A quick go over with the compressed air and we're back down to 30 deg C when idle, and 40 deg C when pushing the system very hard indeed. How many people get to a similar stage and think "Computer's fucked. I need a new one?".