I want to upgrade my Graphics Card to an nVidia 6600GT on my Dell 8300 but to do so I also need to upgrade my PSU which is only 250W. I was wondering has anyone done this successfully, as I have heard there are a lot of problems with doing this. If so could you please give me some info like the new PSU, did you require an adaptor. Basically any info would be appreciated. Thanks a lot....