NVMe mod as optional
[HowTo] Get full NVMe Support for all Systems with an AMI UEFI BIOS - Special Topics / NVMe Support for old Systems - Win-Raid Forum (level1techs.com)
For clean OS install on NVMe and PURE UEFI system, ensure that the vbios of the GTX660 is UEFI, else use GOPupdater
AMD and Nvidia GOP update (No requests, DIY) - BIOS/UEFI Modding / BIOS Modding Guides and Problems - Win-Raid Forum (level1techs.com)
EDIT: Links are valid and working, your browser/country IP restrictions.
Theres MEGA and OneDrive.
Older vbios non-UEFI after GOP inserted will get bigger. Surprise why???
Errors only if the vbios chip is smaller, nothing cant be done or ask a shop to solder a bigger chip.
Read and learn before complain.