Q: Isn’t FireWire a dying horse? Few laptops ship with FireWire ports these days, which makes Inception a useless tool.
A: You can use any interface that expands the PCIe bus, for example PCMCIA, ExpressCards, the new Thunderbolt interface and perhaps SD/IO to hotplug a FireWire interface into the victim machine. The OS will install the necessary drivers on the fly, even when the machine is locked.
Ensure that FireWire drivers are present and not removed from the system
In other words, if you don't have FireWire drivers installed, then this won't do anything; another plus for not installing the drivers for those who have a system with FireWire ports but never need to use them.
My laptop has both FireWire and USB controllers disabled, the former because I never use it and the latter because I almost never use it - and when I do, I find it's not too much hassle to go into the Device Manager and enable the one for the one port I intend to use. Another positive side-effect is that the USB drivers seem to take a rather long time to initialise, so booting is much faster without them.