Selecting the correct M.2 when installing Windows 10

[Rargo]

I'm in the middle of my 1st computer build with custom water cooling.  Have a Corsair MP600 Pro 2TB and a MP600 Force Series 2TB M.2

I want to install Windows on the Pro but since both drives must be installed in advance (due to custom water cooling access) How do I know which one is which when installing Windows?  It will just show 2 drives, both with the same amount of space avail.  Both are preformatted. The Pro is A drive and the Force is the B, will it show the drive letter on the install so I can pick the correct one?

Really do not want to take the loop apart to install the Force drive after installing windows. Will be a major pain. 

 

[Corsair Fer]

Install both drives and take note of which slot you used for the drives. Disable the drive slot through the BIOS for the drive you do not want to install Windows into. 

Install Windows on drive that you want, reboot and reenable the other populated slot.

You will not see a drive letter when selecting which drive to install Windows to by the way to answer your question regarding the drives being preformatted.