So it freezes at random?

Random freezes are generally caused by CPU, or less likely the motherboard itself. Is the CPU fan working, and free of dust? Also, can you try reseating the CPU?

If you having checksum errors, this is a clear indication of faulty RAM, as long as the checksum error is at the same address each time?

the fan seems fine, but i don't know how to reset the CPU. Bare in mind that there's little scope for user input here, and that the PC rarely actually starts...

I'm not sure about the address, it never mentions one. It does, however, say that the memory test went fine.

blip,

Can you tell me exactly what error messages your getting. Is this a checksum error in memory, or a CMOS checksum bad error?

'tis a cmos problem

CMOS checksum errors can sometimes be a result of a serious issue.

Most of the time however, you may just need to replace the motherboard battery. If you or a friend has a multimeter you can test the battery with, this would be good. Its very easy to replace a motherboard battery, you can read instructions here: Smart Computing Article - How To Install A CMOS Battery

Other possible causes are what I mentioned above, loose connections, such as the CPU. There is normally two hooks each side of the fan which need to be unclipped, and then a levar holding the CPU in place.



The CPU will then lift out easily.

This can sometime be a little dangerous process, so if your unsure, your best bet would to leave it to a local computer repair shop, or return it to your manufacturer.