It's not always user-pirated software either! I took my machine to a shop
because it wouldn't boot. They fixed it, but did so by reinstalling Windows
XP from a disk they had kicking around, rather than from my machines
proprietary 'restore' CDs. I didn't know the difference until I signed on
for updates and was informed that my software wasn't 'genuine.' Well, it's
genuine Microsoft, of course, but it wasn't mine. The shop went out of
business in the meantime and my only recourse was to purchase a new user key
from Microsoft, which legitimized the installation of Windows I now had. If
I had instead used the vendor's restoration discs to reinstall the legit,
original copy of Windows, I would have lost all my files and other programs.