How to choose which HDD Windows 10 boots from?

OhParfait

Commendable
Jan 22, 2017
1
0
1,510
Hey all, this might be a little long so skip down a few paragraphs if you want to get straight to the question.

I bought a new WD Black for my PC since the old Seagate that came with it has since filled up. I wanted to keep both drives in the PC since I use the files on the old one but want to continue to have enough space to keep adding more.
The thing was, I wanted to boot my PC from the new drive since it's way faster than the old one. Being stupid, instead of cloning the drive I decided to just do a clean installation of windows on it. This worked, but then I lost a bunch of settings and paths and stuff that I'd had on the old drive. It would take way too long to get it back the exact same way. So, I decided I would just clone the old drive to the new one and work from there.
This is where the major problem happened. I couldn't get the PC to boot from the original drive. I had already wiped the new one, but the PC would either only boot from the windows installation USB or the DBAN cd I used to wipe the old one. If I tried taking all that out so that the HDD was the only bootable option, I got an error saying there was nothing to boot from. Well about 3 hours later after lots of researching I turned on legacy booting (I think?) and was able to clone the old drive to the new one and boot onto the new one manually through the BIOS menu (I should also mention that Windows Boot Manager mysteriously disappeared from the boot order and I still don't know how to get it back).

-------
Here's my actual question

So I now have two HDD's that are the exact same in my PC as far as files and such go. Only difference is that one of them is larger and faster. That's the one I want to boot my PC with, but it's currently still booting from the old and slower one. Is there a way to change so that the PC boots from the newer and faster drive, but still leave the old one in there?
Thanks.