Auntie Placebo

It is a fresh install of Windows 10

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