Helping people with computers... one answer at a time.
The part that concerns me most is why did the behavior change? I assume that you were able to access the partition we're talking about without problem before that.
Unfortunately in reformatting, you've probably lost any data that may have been out there. That's partly what reformatting commonly does: erase the contents of the drive being formatted.
But I sense a little more confusion as well.
You mention that the drive has three partitions. Partitions are simply a way to divide up the space on a single hard drive into different logical drives. So if, for example, your hard drive is 31gig in size, and has three equal sized partitions, then I'd expect each partition to be about 10gig in size.
When you reformat a drive, you're really only reformatting one partition. So when you do that, it erases all the files on that partition, and the result is free space equal to the size of the partition.
In other words, if you have a 31gig drive, and three 10gig partitions, I'd expect pretty much what you're seeing after you reformatted the drive.
Now, if what you mean is that the hard drive is larger than 31gig, and that the single partition on that hard drive should be 31gig, but formats out to only 10gig, then that's a different problem entirely. In fact, I'm not even sure what kind of problem that might be.
If this is Windows XP, I'd start with the disk manager and see what it thinks you really have. Get to the disk manager by:
That will show you all the physical hard drives on your system and within each, the logical drives that each contains.
Once those expectations are cleared up, I would check with the manufacturer of that drive to see if they have any diagnostic software that you might run against it to help understand why the failure happened in the first place.