No, I had the same problem. I have three 2tb drives and an external seagate 3TB drive. the 2TB drives were unformatted, but when taking the 3tb external out of the enclosure and inserting it into the PC, the 3tb drive shows up like you, unknown, and wants to be reformatted. However, when putting back into the external and plugging in USB 3.0, it shows up just fine and data is fine.
My best guess to this issue, is that the drive is improperly formatted, and so you must reformat the drive before you are able to use it.
If you only have one drive, then do it like this:
1) Download Gparted (free) GParted -- Download
2) Burn Gparted to a CD.
3) Boot up the computer into Gparted, while the 3tb drive is inserted.
4) Once in Gparted, delete any and all partitions on the 3tb drive. (NOTE: This will DESTROY all data on the disc!
5) You can either reformat as NTFS in Gparted, or you can leave it blank after you deleted partitions. In the second case, Windows will take care of the formatting for you when you install it.