I am now wondering if it could be the PS that is not enough for the system and that overheating is the cause or if the case fans are not sufficient to cool the CPU, I don't know what temp it is supposed to run at. It's an Intel Pentium 4 ® 3.20GHz and runs at around 54 but I have seen it at 70. ( I do have the computer close to the wall on one side). I also wonder if a faulty graphics card or the type of memory in use might be behind it. I’m still in the dark.
Steve