Installed Windows 10, can't seem to boot old Windows 7 partition :(

Hi there, first post, thanks for the forum!

I just installed Windows 10 and I'm loving it, but I'd love to be able to boot my old Windows 7 partition. I can still see and access all of my Windows 7 files (it's just listed as the D: drive in the file explorer, the C: being my Windows 10 partition) but I don't see a 'choose OS' screen when I startup, nor do I see any other options in the msconfig boot menu or elsewhere. I'm attaching my discmgmt screen if that sheds any light...any help would be greatly appreciated :) Thanks!!

(I should note, I've searched and I can't find answers in other threads...slightly different issues others are having it seems)

My friend pointed me to EasyBCD...did the trick. If anyone else has this issue, you just go to 'add entry' in the main menu of easybcd, select the drive your other OS is on (it was D:) for me, and the next time I restarted I could choose between the two.