Chkdsk External Drive -

Sometimes a failing external drive will suddenly appear as "RAW" in Disk Management (no file system). Running chkdsk on a RAW drive is useless—it will simply say "The type of the file system is RAW. CHKDSK is not available for RAW drives." In this case, do not run chkdsk ; use data recovery software first.

or 100% disk usage when the drive is plugged in. chkdsk external drive