0.79

Guys Please HElp My CPU THrottles down to 0.79 ghz I Tried Throttle Stop but NOT WORKS ONLY THING WORKS is when I first run into BIOS then i wait for fans to move and Click Save And Exit and Then It Runs Normally.But As i remove or attach AC to it, It behaves like again the same :/

I recently bought a Dell XPS 15 9570 second-hand and the warranty has expired, so unfortunately unable to get a replacement. The problem is that about two thirds of the time, the CPU clock speed throttles to 0.79GHz and the whole system grinds to a near-halt: even using file explorer or a single...