@Sevoos
Since the manufacturer of your NVMe SSD doesn’t offer a specific driver for its NVMe Controller, you may only have the following options:
- Download the “pure” generic 32/64bit Phison NVMe driver v1.5.0.0 WHQL for Win7 x86/x64, which I am offering >here<, and load it during the Win7 installation.
- If the first option should not work, I recommend to download the 2 MS NVMe Hotfixes for Win7 and to integrate them both into the boot.wim and install.wim of your Win7 Image. You can find the download links to the MS Hotfixes within the obove linked page as well.