It's been a few years now, but I know a major manufacturer had some windows XP boxes around because they were the newest hardware/software they could get with native parallel port support to interface with their machines.

To give you an idea of the complexity of the manufacturing lines, shutting the machines down and starting them back up again was measured in days. Upgrading them would be obscenely expensive, let alone replacing them, just in the opportunity cost of not making anything alone.