The captive-ntfs driver uses the windows ntfs.sys driver to read/write to ntfs partitions. If that file was corrupted in the first place, then captive-ntfs would be using the same corrupted driver. If you have an XP cd lying around, I'd suggest you boot into that cd, and run the repair console to fix it. If the repair console won't allow you to access the system (it should, since it has its own drivers for accessing the ntfs filesystem), your option would most likely be to use any live cd with captive-ntfs built-in, and open a console as root and type:
Code:
captive-acquire
Somewhere in there is a link to download the service pack which contains an updated ntfs.sys driver so you can use that and replace the corrupted ntfs.sys file once captive is working. I normally don't use linux tools to repair windows systems, but there are alternatives out there, i.e..... xp repair console installed on another partition, bart's winpe (bootable live xp cd), and some others I can't think of at the moment. Bart's winpe won't help you now as you need a running xp system to build it in the first place.

HTH,

Durand