This is an unofficial patch to fix the Vector Markup Language (VML) issue
The official version for XP was issued out of Turn on Windows update (MS rarely do this!) So, it is a Top Priority issue that needs to be addressed ASAP, even if you are lazy with your Security updating OK?

The Zero Day Emergency Response Team (ZERT) has issued a patch for the Vector Markup Language (VML) vulnerability that works for unsupported versions of Microsoft Windows, from Windows 98 right up through Windows 2000, SP3.

http://weblog.infoworld.com/techwatch/archives/008142.html

Link for download here as well http://isotf.org/zert/download.htm