I'm mining my CPU on Suprnova. I would need to know exactly what kind of CPU you have, your amount of memory, what OS, and whether it is 32 or 64 bit. I can only help in 64 bit Windows. I'm not aware of a CPU miner that runs in 32 bit.
I ill use it on wndows 2008 64 bit, 1 CPU ( I have lots of vps)