Click on the the UK/US flag on top. It's all in English too. It's very easy to use.
Also, i'm wondering, what do you mean by new/old Windows XP. There is only one XP and you update using the Windows update option in Internet Explorer. The newest update, called Service Pack 2, includes a firewall but I don't believe it includes an antivirus scanner.
A good free Antivirus scanner is called AVG.
http://www.grisoft.com/us/us_index.php