i installed my new wd 3TB green drive then had to format my os drive when windows came back it made me format my 3TB hd and now only reads as a 750gig im running windows7 ive reinstalled windows several times
If you want to use it as a boot drive, you will indeed need a different motherboard.
If you want to use it as a _data_ drive, you can. If there is any data on it that you need, back it up. Delete all partitions. Use the Disk Mangler to re-initialize the drive, and initialize it as GPT, not the default MBR. Unless you have a very old motherboard, you should be able to see and use the entire 3 GB of the drive for data.
I followed your method but immediately the computer saw the drive as a 750GB HDD with unallocated space. There is nothing to indicate initialize (using Windows 8) so there is no further advancement in getting a 3TB to work as it should.
I installed the hard drive on another desktop running Ubuntu 12.10 and was able to make three 1TB partitions, changed the OS format from Linux to NTFS and copied files (,y video and music collections) to it. However when I put the drive back into the Windows 8 computer it still only showed the 750GB size and was asking me to format drive to proceed. SO it seems I can get full use of the drive only under Linux OS and not windows. Strange though as the Windows 8 computer is one year old and the Linux is approaching 5 years.
Would really like a solution to have this working under Windows.