Try this, go into the bios. set ahci on, set port 5-6 to be ahci also. Since you're loading from scratch anyways it should speed the hd's up a little. I assume all your drives are sata type. Set UEFI boot on if you're booting from the 2tb drive, if not i think you can leave it off.
in the bios set your first boot drive to the 2tb drive that you'll boot from.
reset any memory speed to whatever your memory speed is, i think it defaults to 1333 if not set.
Reboot the computer and like you would do to go into the bios, but instead hit the F12 key to bring up boot sequence. Select your CDROM drive to boot windows 7.
Reinstall win7, at the pick hard drive to load windows 7 screen, you can also load your ahci driver, if all your drives are on sata ports 1-4, just load the AMD driver for AHCI (on gigabyte cdrom) just select browse and find the ahci driver for AMD for win7 or win7x64 whatever you're using and load it. If it loads, it just puts you back to the windows screen. Select refresh, in that screen and then pick the partition (off the 2tb) drive and select continue. It should start loading windows 7. if you hard drive is using the ports 5-6 for the 2tb drive, use the marvell ahci win7 driver.
I just went through this crazyness myself getting my ssd and 3tb drives to work, but now it's working great. Let me know if you stil have problems.