I just read the reviews from customers for that PC on Dell's own website. Other people have complained about similar problems. Some even said that it was the worst Dell PC they'd ever owned. It sounds like the problems are endless with that one. As for your specific problem, I've seen similar things done with other PCs back in the old days of AGP graphics ports (before PCIe came out). Some companies would make the integrated graphics chip use the 3D acceleration of the AGP port exclusively, not allowing an add-on card to use it. So, when someone would try to upgrade their graphics, they would not have any 3D acceleration in games. Something similar may be happening with your PC. It may be best to contact Dell or a community of Dell customers to find someone who specifically knows about your problem. Otherwise, returnign it may be a good idea.