Hi
Lets see if i understood it correclty…
GA-B75M-D3H (rev. 1.0) supports you i7-3770 since bios F.4 (Initial bios)…
Changing from IDE/ATA to AHCI on a boot disk will break the OS…
Changing from IDE/ATA to AHCI causes the bios to corrupt and rebuild a version that doesn’t support my i7 and goes into a loop, forever rebooting. OS does not matter in this case. It would be nice to have AHCI, but I’m afraid that I will have to desolder the bone again. Another way would be to insert a different processor and program it to F4, because there is probably i7 support.
thats why in the guide
it is advised to do a clean OS install upon mod old bios to NVMe, in GPT, no CSM (PURE IEFI), and setting SATA to AHCI, but NVMe disk s wont uses this controller, when users want to stay with old OS…its their problem and choice.
AHCI drivers should install themselves, old or new OS, it doesn’t matter, a clean install is unnecessary, you can even enter safe mode with networking and they will install themselves in this mode, you can also manually if you want, then everything will be fine.
Press ALT + F10 to copy Main BIOS to Backup BIOS.
And you say that such a simple operation will cause that I will be able to test these AHCI without fear … 
At what point do you press it? As the logo will show ?
I’m glad I did, it’s strange that I didn’t get to this information earlier somehow avoided me xD
regards
SW