Win7 cannot see my WD 3TB external

I've been sorting through forums, and have opt'd out to just asking.

I have: Windows 7 - 64bit, Hp pavilion dv7-4265dx laptop, AMD Phenom II, with the newest Bios available on Hp Support website.
I need: My WD 3TB Cavalier external to be readable on my windows machine. (Just bought it from newegg.)

The drive letter will not show itself under my computer, so I cannot format quickly; which isn't terrible, because I plan to encrypt it with Truecrypt. But both Truecrypt and Easeus are only able to detect 2TB, not the full 3. I have even gone to cmd and ran diskscan, but that will only show 2TB. I understand that it's a whole disk size issue; but I've read that some people see two separate partitions, that equal 3, but I don't even get that. Can someone please give me some advice on what I'm doing wrong? Thank you in advance.

[Update] I converted the new unallocated drive to GPT in disk management. Right click drive > convert to GPT Disk... it increased the drive from 2048GB to 2047.87GB.