I discovered the problem when backing up with Seagate's DiscWizard. It said it couldn't read the sectors. I checked with WD software as it is a WD drive. There are problems with some sectors. How about using WD's software to fix the problem sectors?
I discovered the problem sectors, while using Disc Wizard to backup the partition. Then confirmed by using Western Data Life Guard to scan, otherwise, there is no sign at all, as the drive just works fine.
Now which drive should I buy?
Seagate 7200.12 1T
Western Digital 1T