If the Reallocated Sector Count is highlighted with a high count, REPLACE THE DRIVE; they are prone to failure and unexpected capacity loss! While SMART Extended is better, a quick test may be sufficient.

In the Attributes tab, locate the following SMART attributes: Reallocated Sector Count; Reallocation Event Count; Current Pending Sector Count.

To test the drive, select Perform Tests. Click Test type: and select Extended Self-Test.