Hi Jim.
Have you tried mounting the Vista partition from Ubuntu's command-line (Applications->Accessories>Terminal) using the commands in the link I gave above?
The commands are:
Code:
sudo fdisk -l
sudo /bin/bash
mkdir /media/disk
mount -t ntfs-3g /dev/sda1 /media/disk -o force
where /dev/sda1 is replaced with the correct thing given in the fdisk output for the Vista partition.
Addendum:
Also, your bootsector may be corrupted. That could be why Ubuntu didn't detect your Vista partition (I had that problem with my XP partition, when its bootsector got corrupted).
If that is the case, you'll need to boot from your Vista dvd or the neosmart recovery disk, access the Command Prompt, and run:
That will rewrite the boot sector of the "active" partition, which assumedly is your Vista partition. If for some reason, the "active" (and hence, "system") partition is some other partition on your HDD, you can temporarily set the "active" flag using System>Administration>Partition Edit from the Ubuntu desktop (though Gparted calls it "boot" instead of "active) to your Vista partition, then run the command, and so that way the bootsector of Vista's partition will get rewritten instead of the other one.
BTW, sorry for all the confusion earlier. Its obvious now after re-reading this thread that you were talking about the other computer, when you mentioned recovering your files and fixing your system with chkdsk, and I thought you were talking about this one. My bad, I'm sorry.
Addendum:
And in answer to the question in the title of this thread, I believe its probably your hard drive that is the problem.