Windows doubts

i am using windows 2k3 server, suppose if the server restart without my knowldge at unofficial time or night hours, how can i find it using event viewwer

this is reagarding updates, i set up the windows update settings as a automatically.how can i find out the update version number ?, suppose if unistall the previous version patch, how it is?
in my windows folder shows the all updated files, shall i unistall the all files expect recent one?