LAG Please help

My reg is NVIDIA gtx 760m 8gb ram. i7 2.20ghz
Last few days ago my game was playable 56- 61fps (hight setting) without sluttering, i had vsync turn off on in-game setting, and "on" nvidia control panel.
Yesterday, my windows install some updates, so i installed them... after installing them i decide to play NBA 2k14, and found out the game was so laggy,it was like for few seconds it was fine after a moment the fps drop to 10- 15 fps for about 10 to 20 seconds and go back to normal and fps drops again after a seconds..

Please i really need your help...

P.S. i already unistalled the game and install it back but didn't fix the problem..

Wow, thats some high-end gig there.
Anyways, I use ccleaner when it gets messy. Try it

Thanks KevinParker13 for your response... but i dont have that software..

Download it then......