How long does it take for you to crash now? Is it immediate or do you have enough time to access the event viewer to see if there is any critical failure happening?
The nvlddmkm failure you had earlier can be a few things but from experience it's usually GPU or RAM related.
If you can't get anywhere, can you try removing your GPU entirely and starting your PC? Your on-board GPU should take over. See if things go smoothly from there.
You are getting really close to a point where I'd just recommend RMA'ing the whole thing though.
It comes quite fast now, between 2 minutes and 10 minutes while just doing stuff on desktop or browsing in the web..
Its a new failure now, after analyzing the dumpfile its Intelppm.sys