Are you running Sun's Java or Microsoft's Java?
Microsoft more-or-less gave up supporting Java themselves, and now refers
users to Sun.
I have Sun's version 6 update 13. Specifically, when I open a command promt
and type "java -version" without the quotes, I get:
java version "1.6.0_13"
Java(TM) SE Runtime Environment (build 1.6.0_13-b03)
Java HotSpot(TM) Client VM (build 11.3-b02, mixed mode, sharing)
I noticed that there is a newer update, 14, but, do not think thst is
required for XP. But, it should work for XP.
http://www.java.com/en/download/manual.jsp
You can test you java at the following website:
http://www.javatester.org/
Go there and click the box nesr the top of the page that says "test the
version of Java your browser is using".
However, be aware that even if you have the latest Java, some websites may
not work correctly. I had an experience earlier this year that some on-line
game sites said that I needed a newer version, when it fact I had a version
so new that it was beyond their ability to recognize, and so their (wrong)
logic produced an error that said my java was too old. In fact, it was
their website that was too old.