CPU Overheat – Video driver

I have couple of questions:

1- A diagnostic program report that my cpu is over heating. I change the cpu fan three times. Still over heating, what else can i do.I already chack power cord.

2- i found an updated driver for my video adapter,but after i installed it i still got the same old driver. i’ve tried everything with no luck such as remove driver from device manager, have window search for at bootup, have window search for it at adding hardware option.

3- how do i disable Double-Buffering.

Thank you