Windows 7 can still be upgraded, for free, to Windows 10, and that would be advisable since ALL support for Windows 7 will end in January. And yes, there are an increasing number of platforms with no driver support for Windows 7. Whether any specific motherboard or component might be usable with it I can't say, but regardless, upgrading would be smart while you still can. It's fairly certain that as we get closer to the EOL of Windows 7 or after official support ends, that the offer of a free upgrade WILL also end so it's best to do it now.
Also, building a new system and trying to use a Windows installation from a previous platform is a bad idea and usually results in nothing but problems and frustration, so doing a clean install along with the new build is also a very good idea, almost a necessity.
It would be smart to simply purchase other media to transfer those photos to since they are valuable, and it's insanely foolish to have something so personally valuable only saved in a single location anyhow. It is never a question of IF a storage device will fail. The only question is WHEN, and when it does, it's too late. You'll never get that data back without spending thousands of dollars for recovery through a lab, and in many cases, not even then. But a new hard drive for the operating system, because if that drive has been around since the Windows 7 days then it is very old and likely to begin failing soon anyhow. Then buy another drive to store the photos on AND make a second backup of those photos on some other kind of device like a large USB flash drive, DVD discs or another storage drive, because even new drives can fail and if you only have those photos in one place, and that happens, they are gone. Period.