Holy $hit, multi-booting!

[PixelGeek]

I had an old lenovo desktop that had a motherboard go out on it. After some time, I noticed that my other desktop, an Alienware Area 51 R2, had five open drive bays. So, I took my old drives out of my lenovo desktop, and threw them in to the alienware. These drives include

 

An alphabet soup of a drive name: 2TB, no operating system. 

840 EVO: 120Gb, Windows 10

850 EVO: 120Gb, Ubuntu

The factory drive that came in the alienware: 2TB, Windows 10. 

 

If I boot in UEFI mode, the Windows boot manager skips all the new drives, and just goes to the factory drive. If I use Legacy mode, I can dual boot my Ubuntu and the 840 EVO Windows 10. But the factory windows installation doesn't show up in Ubuntu's boot menu. What can a boy do? I didn't have this problem back on my lenovo PC. I could dual boot Ubuntu and Windows all day. Can it not handle more than one Windows 10 install at a time? My little brother and I share this PC, so keeping both Windows 10 installs is a requirement.