I have bought a new graphics card Gigabyte Nvidia GTX 750Ti to ubgrade from 550 Ti, when I put the new card in my pc and turned on after windows installed the new card I had to restart it, now it only shows back screen and B2 in the right corner. This is my PSU http://imgur.com/j3fCMAW, CPU http://imgur.com/eyHQJcX, My mother board is MSI H61M-P20 (G3) and BIOS Version is E7788IMS V1.5. Can someone please help me out and tell me what I should do?