ACPI.sys BSOD Help

[ubuysa]

It's 4 years old. The GPU was only replaced this year though, was previously running a 1660 Super.

If the PSU has been working hard for 4 years it's entirely possible that it' struggling now, especially since you've made it work even harder with that new GPU. I would plan to replace that PSU in the near future.

I disabled RAM overclock and it still BSODs.

OK, that's important information. Thank you

Where should I run this in command prompt? As in, on the troubleshoot options after 3 failed boots? Or in Safe Mode? Or when my PC has booted with virtualisation off?

If you can only run in Safe Mode then run them both from an elevated command prompt in Safe Mode.

I did try running it in the troubleshoot options after 3 failed boots and got Error 87, the cleanup-image option is unknown.

The /Cleanup-Image option is definitely not unknown, if your system thinks it is then either your Windows system is damaged or you mistyped something. You did say in your OP that you'd tried DISM already....

We're at the point where it's stable in Safe Mode but won't boot normally. That generally indicates a bad Windows system.