The motherboard model no. is usually located between the pci slots and will be painted on the board. Your question is puzzling though, usually the size of the hard drive will be determined by what operating system you use. Hard drive memory is cache memory and typically would never reach higer tham 16mb and the bios would have little to do with that either. I think your mixing apples and oranges here. Windows 98 supports hard drives up to 32gig, is your problem that the system is only seeing 8gb of a larger drive?