A friend's WinXP laptop crashed in the middle of installing SP1 for WinXP, rendering it unbootable. As the article notes, the "System Recovery Disk" supplied by some OEMs is really a "System Initialization Disk". So, I had to get the data off the hard drive first.
I used Knoppix to transfer the contents of the "Documents and Settings" folder to another system via the network. Fortunately, I never had to use the backup data: I was able to scrounge up a OEM version of Windows XP (with SP1) that allowed me to reinstall it without wiping out the system.
We had a power failure and lost the network, and in a panic he shut off his computer.
From then on, his disk was unreadable by any Microsoft machine -- his machine wouldn't boot, another IDENTICAL XP laptop wouldn't even recognize it (Microsoft licensing on XP strikes again).
Of course, the disk was readable from the ultrabay on my IBM T21 laptop running RedHat 8 so Linux was able to rescue his files. I haven't heard of knoppix before but it sounds like it might have been able to fix whatever happened to his machine...
Just this weekend I used Linux which I squirreled away in a separate partition on my kids game machine running Windows ME to overcome a parasite infestation which came in over Active-X (of course, MOZILLA isn't affected). It created files which were invisible withing Windows ME, of course, not within LINUX so I was able to delete them.
Linux is pretty damn useful in repair Windows slop...