ehw,
If all solutions fail and you find you can not use the external drive, then
Use DiskPart's CLEAN ALL command on the drive to put you back to a drive which you can format, etc, and use as normal.
CLEAN ALL is going to overwrite each and every byte on the external drive with zeroes.
· type
DiskPart,
Enter key
· type
List disk, Enter key
note the numeral of the disk you want to clean
for example purposes, I’ll be using the numeral 0
· type
Select disk 0, Enter key
· type
Detail disk, Enter key
this info will let you know if you selected correctly
· type
Clean ALL, Enter key
your entire disk is being overwritten with zeros.
This can take a considerable amount of time
· type
EXIT, Enter key (only after Clean is finished)
· type
EXIT, Enter key (this gets you back where you were)