This va-503+ with the much newer WD hard drive is running win 98(not se) and is used to run a proprietory ISA switching/polling card that runs a German made machine that edges ophthalmic lenses and a machine that grinds plastic and polycarbornate material for eyeglasses. The industry has stopped making this item but it suits my needs very well. There is no cdrom or floppy hooked to this pc but I did leave the ide cables hooked up to the ide port just in case I have to hook up a cdrom. I finally also changed the sleeve bearing on the cpu(it was so worned out that I call it a wobble bearing) and now the fan on the power supply is making noises. Luckily, I have about three AT power supplies waiting in the wing if I need them.