I have to upgrade to Windows Movie Maker 2.1, so I want to install SP2. XP SP1 is installed already. What are my options? Can I revert to SP1 once I face issues? I have to continue using Emule, torrent, proxy tools(internet ban circumventing tools like Ultrasurf, Vidalia etc.) I don't want any firewall that can't be disabled totally or any kind of protection. (ps.proxy tunneling websites don't give me what I need.)