PC locks up - due to overheat

[DimPrawn]

AMD junk. Bin it.

Get a modern i7, low power, low heat.

[RonBW]

An instructional video I watched last week, "Person of Interest" seemed to suggest that liquid nitrogen cooling was good for overheating computers.

Cheap as chips. Or bottles of milk.

I'm glad you've moved on from using Dexter as an "instructional video"

[Scrag Meister]

Had an issue a few months back where my main desktop kept crashing after a running for a while.

Turned out to be that the GPU wasn't quite seated right, so I now have my case lying flat on the floor so the GPU is vertical and its hasn't crashed since.

Was a pain to diagnose, but got there in the end.

[LondonManc]

Download Malwarebytes, give it a full scan, fix what's broke.

Eliminate malware/virus problems first - it's the cheapest course of action so makes sense to try it first.