I downloaded and installed Office XP SP3 on my computer running XP Pro Windows SP3 and the install caused the computer to hang. After restarting, Windows reverted to SP2 and all my attempts to reinstall Windows SP3 have caused the computer to hang after the install files had completed. Also no other windows updates would install. I initially did not close Norton 360 whilst installing the Office SP3 although I have tried to reinstall Windows SP3 with Norton disabled but the computer still hangs. I have tried different combinations of automatic updates but with the same result. The computer is still running OK but I am concerned with the security. Any help would be greatly appreciated.