I had someone in the office today tell me that upon rebooting (Windows XP) her computer started running chkdsk and ran all three verifying steps for about 30 minutes before the machine would boot. It was being run on her external hard drive that was plugged in that is used on occasion for off-site file storage. She was smart enough to write down the volume name so we condluded that. She believes that the last time it was removed, she did not use the "safely remove" feature. I'm guessing this might have prompted chkdsk.
However, since the test was taking awhile she walked away and didn't watch the rest of the messages on the screen. It seemed to finish it's checks and it booted into Windows and the drive was accessible. The question is, and I don't remember off-hand, if chkdsk found an a bad error on the drive, would it have haulted when it was done instead of booting into Windows? Like I said, the drive was useable after this. I'm just trying to determine if we should recommend further follow-up testing of the drive.