Recently we purchased some larger hard drives to use to back up with. The problem is that in Windows they only show up as 750 GB. To get the drive to show up as 3 TB, and I had to burn a copy of Gparted. After booting the Gparted, you should be able to see the 3 TB hard disk. Try to create a 3 TB partition. If this fails it is because you’ve already created a partition table on the device (Which was for 750 GB), so we need to create a new partition. To do this click Device -> New Partition Table. Make sure the partition table is set to “GPT”. Then you should be able to create a 3 TB NTFS partition.

After you apply changes and reboot, the device should show as 3TB in Windows.

UPDATE:

I had a problem with another drive recently. I had it hooked up through a USB cradle and it kept showing up as 750GB even in Gparted. I removed the drive from the cradle and hooked it directly up to SATA and the drive showed as 3 TB. I then formatted it with Gparted and it works fine in the USB cradle now (I wrote over 2 TB to the drive to verify it was functioning properly).

UPDATE 2:

We’ve been having problems with the backup drives in the older enclosures. We could setup the drive so the entire 3 TB can be used in the enclosure, however after 3-4 days the volume would become “RAW” and we’d lose all the data on the drive (Good thing it was only backup data). We eventually ordered a new enclosure and that fixed the problems. With the new enclosure we no longer had problems seeing the full 3 TB in Windows either.