[Constant Crashing]

It is a fresh install of Windows 10

[Constant Crashing]

I have just fitted a new motherboard, 16gb RAM and a used CPU.

 Everything else, GPU, PSU, case  etc etc are my originals.

I can log in ok, but no matter what Viewer I use it instantly crashes to my desktop after just a couple of minutes.

I havent tried other games yet, but  the system seems stable for general use. Its is definately this pc, other ones I have are fine.

Can anyone help me?

Motherboard is a new ASUS TUF Z390-pro

CPU is a used intelcore i7-9700k

16GB RAM is Corsair Vengance DDR4 3200mb

GPU is my existing Nvidia GTX 660Ti

ty in hope