Windows XP auto updates issue

I do basic level phone in tech support. Some people see the words tech support, and assume you do support for any computer related problem.

So, after that brief intro, here is my question. I had a customer call in complaing that his computer kept freezing (not anything I can do about that). He had WinXP, and though he didn’t come right out and say it, I would have bet it was pirated. The lead up to the issue was that he had one of those info buttons pop up (you know those ones from the system tray, usually telling you to check microsoft for updates) telling him that updates from were downloaded and ready to be installed. He went through the installation, and right after that he had a error pop up tellling him that some files had been replaced by non-window files (or some wording to that effect) and to insert the XP cd to fix the issue.

I’m not asking for a fix, or anything like that (we wouldn’t support it anyway) but I was curious, is this some clever thing microsoft has come up with to deal with the pirated OS, or maybe some virus, or something else? (apologises if this has been done before, I tried to do a search, and I did have a look around google)