@spivonious: Perhaps I'm just (more) cynical in my old age, but in my experience it rarely works out like that. What actually happens is that it's hooked up to a vital piece of equipment/software and nobody has ever checked that any of it can work on a newer OS. So when it inevitably does fail, everyone goes into panic mode and desperately tries getting NT4 running on modern hardware, which rarely works. There are far more ways that old OS's become a liability than merely security issues.