Borderlands 2 issues out of nowhere?

My computer ran the game perfectly fine without so much as a hiccup on high about 2 months ago, now no matter what the settings (even the very lowest) I have massive frame drops during combat. The specs of my PC are as follows,

Asus p8Z77 MoBo
Intel Core i5 3570k @ 3.4GHz (not OC'd)
8Gb Corsair Vengence @ 1600Mhz
nVidia GTX 660 (EVGA Superclocked) 2GB VRAM
600W Power Supply

Hippster2013-10-09T18:46:22Z

update your drivers like the other guy said. OR you have to many programs in the backround. probably the drivers tho

Anonymous2013-10-09T13:28:30Z

update your drivers....nVidia is to blame