Secondary HDD disappeared after installing Ubuntu alongside Windows 10

[Kenny Tacos]

Today I disconnected my secondary drive (HDD) to plug in and power a disc drive, which I used to install Ubuntu alongside Windows 10 on my SSD. Now my hard drive doesn't show up in File Explorer, or even disk manager. I reseated the cables and heard the drive spin up when I started my PC. So why isn't it showing up? This is a huge problem because it has all of my photos, videos, and games... Please help

My hypotheses:
1) Disabled in the BIOS or something
2) Ubuntu seized the hard drive for itself, even though I didn't mount it or use it in Linux

 

[Kenny Tacos]

Well I booted into Ubuntu for a bit and came back to Windows 10 and the drive reappeared. So idk.