Good HDD diagnostic software

I have an external hard drive that is giving me fits with data corruption when transferring files to it. I want to run a good diagnostic on it to try to figure out if it is a bad drive or something else before I return it, and need suggestions for good software to do this. The manufacturer's own HDD tools software does not work on the external drive, even though it says it should. Support site is of no use whatsoever. Thanks.

 

Here are a few of the Free drive diagnostic tools available on the Major Geeks Drive Utilities page.

Tweaking.com - Disk Error Checking at Next Boot 1.7.1

ScanDefrag 5.7
Note: Project has been abandoned

CheckDiskGUI 1.1.5

 

Have you tried CHKDSK /F ? on the external hard drive.
Have you run virus scan on external hard drive ?
If regular data corruption, then this is often a sign of a failing hard drive.
Did you ensure you chose the correct hard drive to scan with the manufacturers own tool- sometimes it can be a higher letter than it seems - C is the boot drive(unless you have multiple partitions- D could be a dvd/cd rom, and if you have two dvd roms, then that could take you to E, -If you have a recovery partition (like many laptops) you could be up to F. So the external hard drive could be G--............