If your version of XP is updating itself as it should be, you should have I.E. version 7 already installed. I have just acquired a SH laptop - the only way to get a machine with XP on it these days. The machine clearly hadn't been used for quite some time as it promptly downloaded 90 updates as soon as I established its internet connection! One of these was to upgrade it's version of I.E. 6 to I.E. 7. The first job of the newly upgraded browser was to download AVG for virus protection!
If you are not sure what is happening, go on to
www.microsoft.com search for "updates" and the site will check your machine for any important O.S. upgrades that you may have missed.
P.P.