Mystery of the Missing Hard Drive Space

Ralph Campbell, one of the subscribers to my free email Terry’s Computer Tips newsletter wrote to ask:

I just noticed that my 120gb external drive, which I have
partitioned into
two drives does not
seem to contain all the space it’s supposed to.
G: drive has a total of 78 gb available ( Used and free)
H: drive, contains a total of 21 gb available (used and free).

The difference is 21 gb which is a whopping amount of space
to be missing.

I could understand a few megabytes for allocation tables or
what-not, but 20
GIGA-bytes?
That’s more that my D; drive contains!

Where’d the balance go?

I responded to Ralph that he seemed to have a problem that I have had.

I bought a “put it together yourself” external case a couple years ago on a super sale. I put a 40GB in it and was perfectly happy.

Earlier this year, I got a 160 to put in it (someone had them for $40 after rebates). Windows XP would only recognize 120GB in the external case. When I direct-connected the drive, XP saw the whole thing. This appears to be an issue with the USB2/IDE interface in my external drive case, as others report being able to use large drives in current external cases successfully, without special drivers.

The mystery is why Ralph’s drive tops at 100GB and not 120GB or 132GB.

I told him to go to Start, Control Panel, Performance & Maintenance, Administrative Tools, Computer Management, Storage, Disk Management (Local) and to see what it shows.

Did he actually create partitions for the whole visible drive? Since he showed 2 partitions, he might have also left some enpty space.

Ralph wrote back to say:

Bingo, once again Terry.
Thanks for getting me there. It shows that I have almost 50 gb unallocated. The PC “sees” less than the 160, but more than the 120 ( 149), which is still a vast discrepancy from the advertised size.

But this is, as you experienced, an Seagate internal drive loaded into an external case. I do not recall paying attention to the total value when I installed it; it was my first experience at doing that, and did it solo!
So, now the question becomes, is there a way to add the unallocated space to one of the other partitions without reformatting that partition?
No?
Then what’s the procedure for reformatting and adding?
What about bringing the unallocated space on line?
Thanks,
Ralph Campbell

I responded: Go to the same display as before. You should be able to do something like right-click in the unused space – in either the volumes listing at the top or the graphical display at the bottom. The popup context menu will give you the option to create a new partition.

Ralph wrote back to say:

Terry;
New drive space successfully formatted, and available. I didn’t even try to combine it with another drive, although I think there may have been a provision for this. The 50 is large enough.
Thanks, again
Ralph

If we consider the 1024- vs 1000-based counting systems, did Ralph get all his hard drive space?

The hard drive manufacturers use 1,000,000,000 bytes as one gigabyte. Using 1024*1024*1024 as one gigabyte (the way the most of the computer industry does), the corresponding 1024-based measurement for Ralph’s 160 GB hard drive is 149.01 GB. So, Ralph is not missing any hard drive space.

The manufacturers now declare their definition in their advertising and on the boxes, so the fine print says he’s “ok.”