I have a Lenovo P330 Workstation (Coffee Lake Xeon E-2224, C246 Chipset) with Two NVMe drives factory installed, one in M.2 slot and another in in PCIe slot with convert-card

I've created a RAID1 volume with two NVMe drives in UEFI (Intel RAID ROM/EFI BIOS module 17.5.2.4317)

The application I have to use only works properly under Windows 7, but Win7(already integrated with needed hotfixes and drivers) can't recognize the NVMe RAID1 drive during installation, althrough installing under non-RAID mode on NVMe drive works fine

I've tried loading/integrating the newest Win7 Intel RST drivers 14.8 and 15.9, they can recognize RAID controller(VEN_8086&DEV_2822) but still can't recognize the NVMe RAID1 drive

Then I tried vanilla Win8.1U3, it doesn't work either, but works with RST v17 driver loaded during installation

Since there is no Intel RST v17 driver of Win7, is it possible to sign Win8-10 v17 driver to make it working under Win7 like the backported "generic USB 3/XHCI host driver"?

Vendor information of RAID controller below

PCI\VEN_8086&DEV_2822&SUBSYS_314F17AA&REV_10
PCI\VEN_8086&DEV_2822&SUBSYS_314F17AA
PCI\VEN_8086&DEV_2822&CC_010400
PCI\VEN_8086&DEV_2822&CC_0104
 

@Fernando
Thanks for your advice!
1. This machine is for bussiness use, so performance is not that important
3. I've known v17&up's missing iaStorF.sys issue, I was just curious, is it possible to combine v15 inf/iaStorF.sys (v15 inf already has the required Hardware ID, no need to mod it) with v17 iaStorAC.sys and re-sign it?
4. Sorry about that, I will not do that again, I did it because I didn't have the right to access PM

@Fernando
Thanks very much, may I try it(mod+signed driver)? I think I can try installing Win7(with this driver integrated) onto a SATA drive, then clone it to NVMe RAID by Acronis or something to see whether it boots