The main issue is that the WD Elements drives need to be plugged into/out of the the USB Port only when the PC is powered off. This is a major warning which in not included in the small pamphlet included with the drive.
The reason for this is Windows XP is caching (holding in memory without writting to the drive) directory and file information. If the drive is unplugged abruptly, some information about the changes made are not actually on the drive. (If anyone is mature enough to remember the old Unix systems, a power-fail would cause corrupted file systems.)
Flash drives can be plugged/unplugged from the system without corruption. Evidently, the system sees a different characteristic for the external drives.
Hopefully, this warning will be distributed through all possible paths. Does WD have a Twitter account?
Can anyone supply information about the availability of the Scan Disk Utility on the Win8 systems, which can reconcile the Free Block Map with the blocks actually allocated in the existing files. My new WD Elements drive is being used to transfer files between my XP system and my new Win8 system.