Instead Windows will now essentially isolate one of the duplicate hard drives by not mounting it or any of its partitions in Windows, thereby forcing you to investigate the problem before deciding on a course of action.It might even make them worse by having your HD chug without accomplishing anything meaningful. With respect to KillerB, Defrag won't do anything about disk errors. The disk write error is probably due to some bad sectors on your hard drive and/or a failing hard drive.Once this pops up, the current process gets halted and could no longer proceed, affecting any troubleshooting process or disk repair you might be doing. Volume Erase failed Volume Erase failed with the error: “Couldn’t Unmount Disk”. Disk Utility stopped verifying (letter of the hard disk) Couldn’t Unmount Disk.
