CPU Speed below base speed and stuck at 0.79ghz

Question

I have a computer with these specs.

One day my old RAM stop working so I replaced it with another RAM which is exactly same.

But after that I realize my games has so much of FPS drops then I check my BIOS.

Which shows RAM is running at max speed which is supported by my motherboard but my processor speed is 800Mhz. But my processor is of 2.8Ghz.

So, only thing I tried to fix this was ThrottleStop which is temporarily because after restarting system my processor speed again changes to 800Mhz.

Is there any permanent solution to this?

Below are some screenshots of my problem.

This is Task Manager screenshot.

BIOS Main Menu Screenshot that shows processor speed at 800mhz.

This is CPU-Z screenshot.

Answer 1

For me the the solution was replacing the aftermarket power adapter with an OEM one! I tried everything else and was about to give up.