TDSSKiller blocked (fails at 80%): my solution

I have an XP Virtual machine that got badly infected. TDSSKiller could not start, it kept failing at 80%. There are a lot of posts on this point at various forums. The rootkit stops the removal program. I tried a few anti-malware programs; none even detected it, let alone removed it (no doubt the work of the rootkit).
I made a new clean virtual machine (XP install) and mouted the problem virtual disk as a second drive. TDSSKiller ran fine on the clean XP, and got rid of the infection on the second drive.
Then going back to the first virtual machine, the drive was now clean.

In real machines this would work, as long as you could move the physical drive to a clean Windows computer. Or maybe booting with a live Windows CD/DVD would do the trick , with TDSSKiller on a USB stick.