Why will Windows only let me format a hard drive to half its capacity?

August 25, 2004 9:21 AM

Why will Windows only let me format a hard drive to half its capacity? [MI]

We found our old computer's IBM/Hitachi Deskstar 25GP drive in the basement (where it had been sitting untouched for at least a year). I decided to install it into our newer computer (where its 15 GB could come in handy for storing my sisters' MP3s); hoping that it's time in the basement hadn't damaged it. When I installed it, however, Windows would only let me format it as a 7.8 GB drive. Normally, I'd just assume that the drive was damaged after its time in the cellar (even though conditions are actually pretty decent down there - no flooding or anything), and toss it out. However, both the Windows drive error-checking utility and this drive-checker from Hitachi pass the drive with flying colours, leaving me with some hope that its full capacity can be restored. Any ideas?

[Sorry for the delay in posting this. The server was apparently having difficulties.]

posted by kickingtheground to computers & internet (8 comments total)

My first thought would be that your motherboard's BIOS might need to be updated (older motherboards were only designed to recognize up to a certain size drive). But 7.8 GB doesn't sound like a typical cutoff.

Could the drive be partitioned in half and Windows is only recognizing one partition? Have you tried to remove all the partitions and create a new partition for the full 15 GB?
posted by jacobsee at 10:46 AM on August 25, 2004

Here's a significant datapoint you omit: What filesytem are you using on the partition? For that matter, how is the drive partitioned?
posted by majick at 11:23 AM on August 25, 2004

The same thing happened to me once, for reasons I have been too lazy to investigate. The problem was fixed when I replaced the old FAT partition with a new NTFS partition.
posted by Krrrlson at 11:40 AM on August 25, 2004

how do you know the drive is 15GB? you link to the 25GP which claims 20.3 to 25.0
posted by jacobsee at 11:50 AM on August 25, 2004

The drive is 15 GB, which I know because that's what it says on it, and that's what it was in the old computer (the exact model number is DJNA-351520). Also, the BIOS recognizes the drive as 15.4 GB, as does the Hitachi software.

On the old computer, I think I was using FAT16 (seriously - I had it broken up into like 8 partitions of 2 GB each). I don't remember if I somehow erased/reformatted the drive before I put it in storage. When, after a long hiatus, I plugged it into the new(er) computer (which already has a 30 GB drive which works just fine), Windows displayed it as a single ~8 GB partition that was unformatted (in RAW, IIRC), which I then formatted as NTFS (this is in XP Pro).
posted by kickingtheground at 12:17 PM on August 25, 2004

i would try to delete the partition and then create a new one, and then format it as NTFS. your windows cd should let you do this.
posted by jacobsee at 12:41 PM on August 25, 2004

Sounds to me like you should ditch the partition table entirely and start over from scratch. I usually just use a linux boot disk to do stuff like this -- cfdisk -z /dev/hdc works miracles on hosed partition tables -- so I'm not entirely sure what your options are on the Windows side of things to nuke the partition table.
posted by majick at 12:43 PM on August 25, 2004

Anyway, I got it to work, with something akin to majick's suggestion. That is, I did a low-level format on the thing, and even deleted the boot partition, and now windows let me create a >14GB partition.

Thanks guys!
posted by kickingtheground at 9:49 PM on August 25, 2004