I have a 20gb hard drive that is only formatting to 15.9 GB.  I do not see any hidden partition in either computer management or diskpart.  I know that it should be about 18.6 gb in size.  Any ideas?PATIO,

Thanks for posting the table.  Like I said in the original post, I know it's supposed to format out to about 18.6 GB but it is only formatting to about 15.9 GB, way less than what the table shows.  I am CHECKING these drives via a usb cable using windows XP Pro on the machine checking the drives.  DISK management in XP does not show any hidden partitions nor does DISKPART utiltiy.How was it formatted and what format is it ? ?
Diskpart should show it correctly...
used disk manager to format it.  Deleted all partitions first.  Formatted in NTFS.
Did it ever have Linux on it that you know of ? ?It might have.  The drives came from IBM laptops with windows XP pro and, if I am not mistaken, they use linux for their OS RECOVERY partition.Could be bad sectors on the disk.
Run chkdisk.Always run chkdsk with the repair option.  No luck.Then there's probably a hidden restore partition on there...
The only way to check this would be to track down what type of machine it came out of...
Although i STILL say diskpart should show it...

IDEA: DLoad and install the Free ver. of Easus partition manager and see it that picks it up...