mad harddrive disease: problematic tar file created on hard drive with bad sectors

Hello,

I have a dual-boot laptop that began to exhibit a failing harddrive. winXP would no longer boot. Linux was able to come up, but only after fsck-ing bad blocks in some linux partitions.

After mounting the winXP partition, I created, in a linux partition, a 2GB tar file containing the winXP Thunderbird email client Inbox, and then ftp'd that over to another winXP machine.

This succeeded, sortof:

1) On the winXP destination drive, Thunderbird was able to open the ftp'd, untarred Inbox, and I had access to all the emails that I attempted to open.

2) a first attempt to ftp the file to another linux box ended in a hung transfer, uninterruptible sleep, and the consequent demise of the linux destination drive.

3) StorageCraft baremetal backup for the winXP destination drive, containing the transferred Inbox file, churns for hours with CRC errors.

4) Now, immediately following a Thunderbird update on the winXP destination drive, Thunderbird
fails to run.

So those bad sectors on the source drive appear to be problematically represented on the destination drive. I need to fix that.

I'm considering going back to the source drive, fsck-ing the winXP partition, and starting over. However, I'd sincerely like to avoid more any more uninterruptible i/o, so i hesitate to do this.

I'd mostly like to understand what the problem tar file looks like at the bit or block level.

What does a bad block look like in a tar file ... does it default to some junk, or are the surrounding blocks concatenated together, ignoring the holes, and screwing up the metadata?

How can I clean up my 2GB madcow Inbox?

Thanks!
Paul