Most Games keep randomly crashing

Hello, I've recently bought a new graphics card and everything went down from there. Almost all the games that I play just randomly crash, some crash after a minute with no warning or error displayed, others after several minutes, others after 1-2 hours.

I bought the MSI GeForce GTX 970 GAMING OC 4GB DDR5 256-bit and upgraded from an older AMD graphics card but the funny thing is everything worked on the older card, on low or medium settings but every game worked without any issues.

My other specs are:

Sirtec High Power Element BRONZE II 600W PSU

HyperX Savage 8GB DDR3 1600MHz RAM

Procesor Intel Haswell Refresh, Core i5 4460 3.2GHz box

Hard disk Seagate Desktop HDD 1TB 7200RPM 64MB SATA-III

ASRock B85M Pro3 Motherboard

Nvidia Experience and other applications tell me that I can run pretty much anything on Ultra and High. And everything I play stays at 60 FPS smooth, no stuttering, nothing bad before crashing.

So what can the issue be ?

So far I've uninstalled the latest Nvidia drivers and tried an older version, the issue still persists.

I uninstalled Nvidia Experience as I've heard it can make games crash and underperform.

I underclocked the GPU, I never overclocked it yet.

I even rebooted the windows to have everything fresh and it still happens.

I've looked through various applications like MSI Afterburner and MSI Gaming App, there is nothing wrong with the GPU, it works at normal parameters, at least as far as I can tell.