Thanks for the response. I contacted ATI and Dell after my post and found out that there was an OEM video decoder card that I also had to remove in addition to the video card I replaced. When I did that, the ATI worked perfectly. It plays perfectly with no stuttering or hesitation. And this is with a 400mh machine. I tried WinDVD and PowerDVD with the original video card and there were hesitations with both software programs. There are no problems with the ATI card and the ATI DVDsoftware player. Thanks again for trying to help.