AMD Radeon HD 7750

Hello. I have a old PowerEdge T110 II server that I put a AMD Radeon 7750 graphics card in. For the frist month or so it worked great. Now my screen will freeze with purple squares everywhere. Here is an image link: Image I usually just restart my PC and it goes fine. But then I lose everything...

Alright, so the build is currently as follows Case: NZXT phantom 410 black (not really looking for anything other than the phantom series) CPU: Intel core i5 4670K processor. 3.40 ghz w/6mb cache (http://www.memoryexpress.com/Products/MX45783) (not sure if i need the 4670K, i don't know much...