[SOLVED] Upgraded to Windows 10, Now One HD Partition is missing

[RS13]

I just installed Windows 10 on my primary hard drive. But I had a secondary hard drive that was partioned and after the update only one of the partitions is showing up. When I look at it in the disk management tool, it says that half the hard drive is unallocated. What's going on here and how do I get my data back?

PS. I know I didn't accidentally delete that partition: This drive was not even connected when I installed Windows 10.

 

[USAFRet]

Screencaps of what is showing you this, please.

 

[RS13]

Since TH doesn't allow me to upload screencaps, it looks like this, except all the New Volume options are greyed out.

 

[jeremyj_83]

Since TH doesn't allow me to upload screencaps, it looks like this, except all the New Volume options are greyed out.

Have you initialized the disk?

 

[RS13]

How do I initialize a partition? I know how to initialize hard drive, but I see no options to do that for the partition. All I see when I right click on it is three greyed out "new volume" options, properties and help (which is of no help).

 

[RS13]

OK, I figured out what the problem was. I was using a 4 TB hard drive from seagate and I needed to download and a program called "Seagate extended capacity manager" from here: https://www.seagate.com/support/downloads/beyond-2tb/.

I think I must of used a 3rd party program last time, because I have no recollection of ever using that program. But anyways, if anyone else has that problem, now you know.