File Read Test is a tool that reads disk files or directories and stops on the first read error. A second tool, Quick Disk Test, fills a disk with test data and verifies that it can be read back without errors.
I am very satisfied with this lightweight application. I find it extremely useful. Warmly recommended. The only downside, for me personally is the fact that file (and perhaps folder) counts at the end of the scan, are incorrect. Namely, when using directory test mode, the program incorrectly reports greater than actual, number of files. This is not a huge problem, as this little program performs it's function admirably. A big "thank you" to the author!