> All I can remember doing in the last year was attempting to update a video driver.
Do you have an older Nvidia video card?
There was an issue a while back with newer Nvidia drivers on older cards crashing MAME. It was a driver issue, not a MAME issue. I think it was happening on all games though, not just Neo Geo.
Are you doing any overclocking? Maybe running those specific games are causing the CPU to crash for whatever reason due to overclocking.