well, I feel like a complete dumbass. since i have a very small computer, and the radeon hd 7770 is a kind of big card, the GPU was over my hard drive SATA cables, preventing it from being plugged in all the way. it is not running just fine. Thank you all for your help, and sorry to waste your time talking about drivers and BIOS and PSUs and stuff like that, when it was just me being plain stupid. (i plugged in my hard drive to another slot)