I have a Compaq/HP desk top which I've had for nearly 5 years. It's a 64 bit system with 4G of memory. The OS is windows 7. All of a sudden it freezes up. I can shut it down and when it boots up, it's fine for just a few minutes and then it freezes up again. I've tried restarting several times but the same thing happens. Maybe it's seen its better days. Any thoughts as to what the problem might be?