PC is 3 months outside of warranty coverage. OH BOY CRASH TIME

Need some suggestions or just help. Windows support have said it’s not Windows and likely a hardware (RAM etc) issue. It’s crashed completely when idling or when tuning the SYS/ScanNow as admin.

I’ve also got the fltrmng error - but mostly it crashes with a blank screen and just resets. Booting into the repair mode thing after 3 resets, runs into an error and can’t repair. Going into settings and trying to reinstall windows via network connection? 100% then crash

Last time I ran the memory diagnostic tool, it showed no errors. They’ve now suggested running MemTest86 overnight.

Specs:
Intel i9 (can’t check exact model/series as PC running the memory diagnostic again)
RTX 4090
96GB Corsair RAM
2 x 2TB SSDs