All right well I had more time on my hands than I thought, so I managed to find the answer. Here's the link:
http://news.zdnet.co.uk/business/0,3...2129825,00.htm
Here's the relevant explanation:
Microsoft released Service Pack 1, the first major collection of Windows XP bug fixes, in September. The update added Microsoft's version of the Java Virtual Machine (JVM), which the company had decided not to ship with the operating system launched in October 2001. The revised service pack, version 1a, removes Microsoft's JVM, as ordered by a Baltimore court.
Edit to add: Thank you very much SiphonX!!!