Oops, reading that does seem rather ambiguous, sorry. I'm only upgrading the GPU and I want to buy W7 as well (the copy i have right now isn't fully functional). I put the PSU in there cause the template told me to, and the wattage is important when buying a GPU, right?
edit: Yeah, I really liked the card I had, but it had some major heat issues and it would cause my computer to crash a lot and it's too late to RMA now. I took it out and have been using the Intel graphics from my i5 2400 cpu, and it hasn't crashed for a few weeks.
Thanks for giving me a starting place to start looking!
So i've found the Radeon HD 7870 which needs 500W of PSU (which I have) but on the AMD website it has a list of certified PSU's, and mine isn't on the list... do you think that it would really matter? I mean, i have the recommended wattage, it's just not on their list.
Your PSU is decent. Companies just want more money, so they get put on their list. OCZ is a solid company (amazing SSDs by the way). If you can shell out a slight amount more for the 7870, that would do you good.