It's your pride-and-joy, so maintenance is important. Darren Yates gives you his hit-list of things to watch out for.
KEEP THE CPU COOLER CLEAN
Nothing robs your PC of speed like an overheating CPU. I managed to even surprise myself recently when I noticed dust gathering underneath the CPU fan above the heatsink fins on my CPU cooler — surprising because the PC is a good metre off the floor. No matter how much you vacuum carpeted floors, dust will eventually clog up the heatsink or filters on your PC case — naturally dusty environments don't help either. With no airflow, you get no cooling, CPU temps rise and performance drops off a cliff. Do a six-monthly check just to make sure your PC thermally stays in good condition.