It's nothing ot do with the OS, as even the latest computers can run DOS! The problem is in needing ISA slots, which is where we are, also. The company that makes the machine I'm talking about wants something like $5k to upgrade. It comes with a new PC, interface board, software, and not much else, not even a new monitor or printer, both which are required. The only problem we might run into by DIY'ing it is compatibility with a different motherboard, as they go on and on about how the boards are specific to them, etc.... I have a feeling that it's just a QC and support thing, seeing how hardware was so flaky back then, at times.