System Reserved Issue on new PC

[Ratski633]

I've just finished my second build and have run into a problem,
I installed Windows 10 onto a new SSD (480GB), all appeared to go ok. Rebooted and then connected a 2TB HDD for storage. I now find this is labelled as "System Reserved" 67.9 MB free of 99.MB and the rest of the 2TB is completely unusable.
I've only installed a couple of programs(and have my backup from my old PC) so I could reinstall Win 10 again, if this is the way forward? I don't understand why/how it happened in the first place, only the SSD was connected.
Do I need to wipe both the SSD and the HDD before reinstalling and, if so how? And how do I stop it from happening again?
I hope someone has an idiots guide of how to proceed.
Many thanks.

 

[ArtPog]

Just to review & confirm your situation...

1. What do you mean when you indicate you "just finished my second build..."? That 2 TB troublesome HDD was installed in a previous "build"?
What was its function? Contained an OS?

2. In any event, you fresh-installed(?) Win 10 on a "virgin" SSD on this new build. At the time of this installation the SSD was the only disk connected in the system, right? The 2 TB HDD was nowhere to be seen at this time, yes?

And the system booted and properly functioned without any problems, yes?

3. But now when you install the HDD as a secondary drive in the system only a single partition of 99 MB ("System Reserved") is reflected. (The SR partition obviously refers to a previous OS, presumably a Win 7 installation.)

And you say the remaining disk-space is "completely unusable"? What exactly does this mean? The disk-space is shown as "unallocated"? And you can't create one or more partitions in that unallocated disk-space?