I have 3 DELL DIMENSION 8100s all running xp, ie6, wmp9, vlc, wmp 6.4, and gom. I created a DVD copy of a home made VHS. I used a GO VIDEO brand model VR3840 combo unit. After finalization the DVD ran in all 4 of my stand alones, but only one of my three towers. They are all equipped with one DVD ROM, and one CD WRITER. All are of various models. They are all set to CS. They all play commercial dvds, protected or not. The 3840 uses MINUS DVDs, both Rs and RWs. Is it possible that only ONE of the 3 ROM drives can read MINUS DVDs? While the other 2 can only read PLUS DVDs? Is it worth it to replace the drive with a MULTI READ? Which one? My combo unit can record both dvd to vhs and the reverse. My other combo can record dvd to vhs only. Both read PLUS and MINUS FINALIZED DVDs. Why the incompatibility? I want to fix the tower if I can. The rest I can live with.