I recently purchased Hard Disk Sentinel. I did a Write/Read surface test against an external USB backup drive. The test reported 0 errors. But after the test was completed, the drive became unrecognizable to Windows. Sentinel support is telling me that this is normal because all the partition information is overwritten during the Write/Read test, and therefore one would need to reformat the disk after the Write/Read test is completed. Is this true with all similar disk utility tools? For instance, if I use the "Erase" option in HDDScan, would I need to reformat the drive after the test is completed?