Before i Install 2010 i have two questions please ?????

Hello

            WIN XP/SP2  I.E 6x/ NISS 2009

                            Just received the 167 2 11 update .... a few question please:

      

                1.  going to update to Win SP3 ...as i understand the 'instructions,  it encourages disabling one's a/v program when downloading/installing XP3  - when i right click on the taskbar icon there is the choice to disable the firewall and the a/v 'autoprotect'... seems easy enough ''but' what happens to any 'protection' during the download from Microsoft? ...( i know to close-out all other programs);

                       Is it better  to keep NISS active  but   'save' the sp3 download to desktop, close-out I.E 6/sign-off the internet and   ''then'' disable autoprotect for the a/v/firewall and do the install ''off line'' that way ?

                       

                2.  is it best to update to SP3 'first' and then update to 2010?  From what i've been reading here since i now have the latest 167 2 7 11 it's o.k. to install 2010 right 'over 2009 (no need to uninstall (gasp) and then do the new install ?) 

    thanks in advance for any advices.... remember, i'm a 'white-knuckle' flyer !!!      regards - Edythe