I had that dell computer that you had. I'm 95% sure that the PSU is a different size to standard PSU's, so you can not upgrade it. I can't say about the graphics card - I upgraded mine but it was only 1 expansion slot high, not 2. If I were you, I would just go the whole way and ditch dell. Buy a case, a new motherboard, a new PSU and a new GFX card. Yes, it will be a lot more expensive. But if your motherboard/PSU breaks in that current setup, you're going to have to do that anyway. It is a lot better to ditch Dell's non-standard parts and get fully standard easily upgradable parts, so you can just replace the components that fail - not the entire computer. I highly reccomend doing this. Tech details of case: it is BTx format, not ATx format (which is standard). The PSU is more square in this dell case, and will not fit in ATx cases. The motherboard is the same. I had this exact machine and those are the problems I faced.