Since both systems are Windows systems (meaning we're not likely going to have to deal with different format types other than NTFS or FAT), there is a much easier way to get at the data. Simply pull the problematic system's hard drive out of the case, connect it to the other functional PC, and copy/move the data you want directly. You can do this either internally by connecting the problematic system's hard drive to an available IDE port on the good system (which could be a little more complicated if the problematic system's hard drive is a PATA type hard drive where master/slave settings might be involved), or use an external hard drive enclosure so that you can connect the problematic system's hard drive to an available USB port on the good system. As long as you don't try and boot from the problematic system's hard drive (which won't boot anyway), you can still likely access the data on it with another PC. No Linux, no Samba, no bull-squat. And if you choose the internal connection method, copying/moving data is about as fast as it can get too.
Now, if you just don't want to open up both PC's cause of warranty concerns or something then you could use a "live" Linux distro to copy/move data. And it sounds like that's what you may have been trying to do with Knoppix - and not necessarily locally either. But this method is harder and can be complicated and/or very problematic especially if you involve networking with a more "advanced" or "less polished" distro like Knoppix. But if you have no choice (cause you only have one PC, for example) then I would at least suggest you use a more modern Linux distro such as Ubuntu 10 (even as old as Ubuntu 7). Unlike Knoppix, Ubuntu is nearly as simple as using Microsoft Windows especially when it comes to copying/moving files and even with most networking issues too. And if it's preparation/recovery tools that you need, I suspect Ubuntu even has Ultimate Boot CD beat as well. So stop using Knoppix and Ultimate Boot and get yourself a FREE copy of Ubuntu 10.10 desktop 32-bit version (the 32-bit version is more likely to work on anything - even 64-bit machines).
So, to sum it up, you might try attaching the problematic systems's hard drive to another functional PC and copy/move (recover) the data that way. But if you can't do that then it gets a little more complicated with Linux where I secondarily suggest using Ubuntu rather than Knoppix or even Ultimate Boot CD. Cause once you boot with Ubuntu it's really just a simple matter of copying/moving data from somewhere (like the problematic system's hard drive) to somewhere (like a USB memory stick or even over a LAN). Good luck.