Thanks for the reply. I tried that already. I even tried the ultimate test: booting up on a CD-R that works on all the other pc’s I worked on (a lot), and it didn’t work. Every CD-R inserted, even written ones, show up as blank. I’ve already searched (almost) all the other posts here, and tried all the suggestions, such as upper/lower filters etc. Evidently it,s a firmware or hardware problem, not a driver or registry problem. Thanx everyone for their help.