Ubuntu :: Windows Corrupted NTFS External Usb Hdd - How To Recover

I had a perfectly working Western Digital 250GB external usb hdd about 30 minutes ago. It has about 130GB of data I spent 3 hours copying to it yesterday from my Ubuntu laptop. Just to test it, I plugged it into an older Windows XP machine, and it seemed to work just fine. Then I tried to do the "Safely Remove Hardware" thing. It told me that it could not remove the external drive because another program was accessing it. So okay, I just wait a minute or two. Try again -- same thing. Tried it several more times, waiting a minute or two between each try -- same thing. Then suddenly a message pops up -- cannot write to drive. I also get another error: drive is corrupt, run chkdsk utility. Makes no sense. I was accessing files from the drive from within Windows just fine minutes before.

So since it won't "unmount safely", I just unplug it (probably a mistake, but I didn't see that I had any other choice at the moment), then try mounting it using a LiveCD of Puppy Linux -- Puppy will not mount it, just gives an error but no details.

My Ubuntu laptop, however, is no longer usable -- after I copied the 130GB of files I wanted to save to my external hdd, I attempted an upgrade of Ubuntu. It hosed. I'm still on that Puppy Linux LiveCD right now as I type.

So then. I KNOW this external hdd should be recoverable. I didn't do anything to it except let Windows screw up its ability to be mounted/unmounted, somehow. But I do not know how to go about trying to rescue it. What are the tools I should use? Is there something I can download somewhere that I can burn to a bootable CD or something that can fix a broken NTFS drive/partition? It would almost have to be something bootable at this point since I don't know how to install anything new on Puppy. Wasn't there an "Ultimate Linux Bootable Rescue CD" or something like that a while back? I can't remember it's exact name now.

If worst comes to worst, I suppose I could always reformat the external hdd and then copy the files over to it again. I still have all my files on my laptop's hard drive and Puppy can see them -- the Ubuntu upgrade I attempted did not overwrite all my stuff. But....I would just rather avoid having to spend another 3 hours or more today doing that. All my files are already on the external....I just want to fix it so that I can see them again.