Weird screen crashes

Hi,

For few days I'm trying to install and run Zorin OS 12.4 64bit normally. Unfortunately every time - take it during installation or after - something bad happens. Now there's only one problem left(I hope) - after opening several tabs screen goes crazy and only restarting pc helps. I'm attaching pictures of the screen crashed. It used to crash like this during installation few times.

It seemed too me there's problem with GPU because of the screen crashing, but since it happens after opening several programs maybe it's RAM problem? Before that I run some torture test using Mprime for CPU and Memory and everything was fine even after 9h of testing. The last time it happend only Chromium, Maps and Weather were opened.

https://imgur.com/0Z7dzyc
https://imgur.com/RqoLmn1

Here's my pc setting(problem occurs with and without overclocking of CPU and RAM):
- AsRock N68C-S UCC motherboard
- Phenom II x2 560 3.3GHz
- 4GB of Kingston RAM (also tested with memtest some time ago and everything was fine)
- Kingston SSD 120GB

Thanks for your help in advance!

Could you provide me with what GPU is being used? Is it an integrated video chip set on the motherboard or separate graphics card? Are you using AMD or nvidia? Proprietary (nvidia) or nouveau drivers?

The screen crash can be due to the failure of the hard disk or the random access memory. It can also e due to the hardware failure and you can also check the BIOS settings.