We had this attack in a few of our legacy Win2k machines where i work, it was only a handful of machines but it still astounds me that such a big company can be running obsolete, non-supported OS.
Bigger the company, or more specifically greater the amount of computers, the bigger the cost in upgrading them all, both time and money, and more likely management are to say "look like they're working fine to me".
IT is one of those things that gets it in the neck when it's working and twice when it isn't.