Matthew_51 :
so i have a $900 pc and i never had any issues with frames or anything like that now all of a sudden im getting really low frames on games that i can run on ultra and get 150 frames im running on low and getting 15 and also my browser is really slow and i cant watch hd videos my specs are intel i5 4590 geforce gtx 960 4gb 8gb of ram and windows 8.1 HELPPP
I got the same specs as you!
Also have you updated your graphics driver to the newest 2.10.0.66 from Nvidia? If you did, you might want to go back to the previous driver since the newest brought down my games fps and started crashing my programs. After going to the previous they went back to normal.
Also try defrag the hard drive (usually helps) virus check, and all that.