Need your help for using unsigned modified drivers

The short story is that I have an older (very older) 3rd gen intel laptop that works really great. Intel dropped support for it and since windows7 there have not released any update drivers for the USB3 port (Intel(R) USB 3.0 eXtensible Host Controller) . So on most of my External USB 3 hard disks I get nonstop disconnections and I am not able to use them. Unfortunately I was not able to find any working drivers for my laptop, so I modified the last windows7 drivers and installed them on windows 11. Surprisingly the drivers are working perfectly fine and all my hard disks are again working normally!

The problem is that now that I have modified the drivers windows 11 says that they are unsigned and I am only able to use them after disabling secure boot in bios and disabling driver signature verification in Windows. This is certainly not the best solution!

I know that it's possible to sign drivers, but I don't know how this can be done. Can someone please help me add a valid signature to these drivers and use them normally or tell me what's the best solution in my case?

I have attached the drivers as zip file in case someone want to check them out.