I recently built a new system with Win7 Home Premium on an OCZ Vertex 4 and a Seagate Barracuda 3TB Storage drive. When I go into start-computer-manage-disk management, there is about 1TB of unallocated space that I can't merge with the rest of the drive for some reason. The "extend volume" option is whited out on the usable part of the drive. Is this just a fixable gimmick, or is my drive bad?