Of course there are some differences! First, the sp2 contains more security patches than the sp1 does. But now since sp3 is already out, i hightly recommend your system patched with sp3 to prevent the attack of many viruses or torjans. Remember to keep your windows sytem updated everyday. Second, the professional XP has more powerful network management related components than the home edition has as far as I remembered. Genernally, the home edition is enough for our ordinary usage.