First thing I did was to check both the card and the motherboard; both should work with Windows 7. There's a lot of hardware out not that won't work without 10. The motherboard supports VGA and HDMI connectors, does your processor support video (for all I know, all processors for that board do and it was a stupid question.)
If so, the first thing that I would suggest is installing Windows using the onboard graphics. Or is that what you did? If that's what you did, my inexpert guess would be a problem with the card, since that's the component that's failing.
As I noted above, I'm fairly ignorant these days. Another possibility is that the card requires an older BIOS board and the board only supports UEFI, but you'd need help from someone who knows what s/he is doing on that. Have you tried the card in another machine and ensured that it works?