i have been trying to install win 7 on my pc, wich allready have win 10.
First i tried to make a new partition on my m.2 drive, in the hope that i COULD install win 7 on the partition, but win 7 couldn't see my m.2 SSD, no matter what drivers i tried to put into the Boot Usb, so i gave up.
Instead i tried to install it to an old SSD. so i formatted the SSD MADE my bootable usb, and it worked. now when i boot my pc, i can PRESS F12(boot options) and choose to boot from the SSD with WINDOWS 7 installed.
when i do tho, it says one of my disks needs to be checked, and it will GO through the checking process and restart, i can then press F12 again, and it will check it again.
I can still boot my win 10 without any problems, but i need win7 for an old program.
If anyone have some advice to this, i'd love to hear it.

Motherboard       - auorus x470 gaming 7 wifi
m.2 SSD            - Corsair Force MP510 M.2 SSD - 960GB
SSD with win 7 i - 500 GB Samsung 850 EVO SSD

if you need more info, just ask and i'll find