As you seem to already know, seeing the users for the hard disk that is NOT in the laptop doesn't make much sense. I looked at the Acer website, could find that model number, but clicking it only gives me a blank page with no information. The only way that I can figure what you describe could be happening would be if you were using some sort of "ready boost" flash drive to help with booting (and that drive stored the bogus users). As far as I can tell from reviews of that model Acer, it doesn't have any such magic feature built in, and I would expect that you knew not to use a Win 7 ready boost drive while you were booting a vista hard disk, but unless something like that happened I don't have any idea on what caused this.

I'm not a Win 7 user, so there may be things that you can still do to recover Win 7 that I have no knowledge of. Don't rush to do any of what I say below before you rule out a more simple fix.

Knoppix (and other Live Linux CDs and DVDs) likely can still read the hard disk and allow you to recover data. There are many ways that you could do this, depending on how much you need to recover and what resources you have available to you. Here are some ways that this can be approached:

1) A FAT formatted flash drive can be used to hold files. Mount the drive read/write and copy the needed files to it. Be sure to unmount it before removing it from the Linux system.

2) You could write the files to CD or DVD. (You may find this easier with Knoppix 5.x than with 6.x versions). One complication to this is you can't write to optical disk while running from the same booted optical disc drive, so you either need two drives (unlikely on a laptop) or enough memory to use the "toram" boot option to copy the disc to ram and free up the drive.

3) you could e-mail the files to yourself, or transfer them to any internet storage location (such as an FTP server or a site dedicated to file storage).

4) The way that I often use is to transfer the files to another Windows machine on the local network. I like to use FTP to do this, and install a free Windows FTP server on the target system, then use Konquror or a browser as the FTP client on the Linux system (I expect you could also use native Linux FTP clients, but I have not done it that way).

Good luck.