The processors are Intel core duo 6400.
I purchased two computers from an asset realisation. The computers have the Microsoft sticker and an OEM Windows XP cdrom and nothing else. One computer has a g33M-s2 motherboard while the other has a ga-vm900m rev 1.
I have now downloaded the drivers for each of these motherboards from the Gigabyte site, and, given your earlier advice, have selected the 32 bit versions.
The driver cdrom did not come with the computers.
cheers and thanks