I might as well give the solution to "How to install Windows on a AMD RAIDExpress2 array" here also.
1 - Setup your array in bios.
2 - Boot from Windows installer USB or Ventoy selecting WIM mode.
3 - Load driver from a USB stick.
- When windows installer cant find your array. Plugin your second USB stick that you have copied the extracted Raid driver you downloaded to and click "Load Driver"
- Browse to the usb stick driver folder and select folders in order:
1: rcbottom - it might show you several lines of drivers, just select last one and click Load...
2: rcraid - Click Load...
3: rccfg - Click Load...
Now you should see your array. But one IMPORTANT step before you proceed!
4 - Unplug your USB STICK you loaded the driver from!
- For some reason or another it seems if you just select your array and click next on the installer it will not be able to boot when rebooting... it will cause Windows to panic and break when it reboots and you need to do it all over again. Or it will install nicely, work great with fresh Windows and then in a few days when you remember to unplug your usb stick from behind your computer it will not boot anymore...
5 - Select your raid array and click Next.
- Let windows copy its files and just to be safe as soon as it reboots yank out the installer usb stick also.