Okay to make quick, I'll ask this, Why isn't my graphics card ,(Sapphire Radeon R7 240 1 GB) working with my desktop!? Desktop is a (Compaq Presario CQ5500F)... Things to know beforehand: I replaced the CPU with an (AMD Phenom X4 9750) and the PSU with an 800W PSU. I'll be MORE THAN WILLING to provide more information if what I shared is insufficient to your understanding on why this graphics card isn't working. I mean it fits in its slot and the little fan even spins... I'm really frustrated and just want to game it.