So I have a 1TB HDD, 240GB SSD and a new 2TB HDD. under PC all I see is this http://prntscr.com/nzfwlk, Why is my 2TB not showing up? its plugged in and it shows in my UEFI that it is connected.
You probably have to initialize and format the disk. Open up disk management, easiest way is to right click the start button or press window+X. Disk management should be about halfway down the menu. Your 2TB HDD should be there but you probably have to right click and initialize it, then right click it again after initializing it and format it. Since you have UEFI it's probably best to initialize it as GPT.