Reinstallation of XP should not be necessary for that. Open Control Panel, then open Automatic Updates, and choose the preferred option. But I'm afraid that might be the only thing possible with the Office issue...uninstall Office, which should also uninstall the updates, reinstall it, and cherry-pick the updates you allow. Before you do that, and if you are pretty sure that you know when it arrived, try doing a "System Restore" to a point prior to that date. Of course, that also kills anything else you installed since then.