I used Eraser on my external USB hard drive and then used Recuva to verify that files were not recoverable. Recuva successfully recovered files, so I did another pass with Eraser. However, now when I try to use Recuva again to validate that the drive is clean, Recuva crashes as soon as I hit start scan on that drive. It still works on other drives. I have tried doing a quick reformat on the drive, a full reformat, changed the drive letter, but it always crashes with that drive.