Master Reboot

Hello,


My neighbor has a Gateway GT5432 desktop pc....I am trying to do a master reboot without her Gateway original disk that came with it....I have looked everywhere online and can't find how to do a master reboot....I have tried to do the F11 key and it won't let me do that is just goes on to her Vista screen where she logs on with her admin password....How can I get it to do what I am trying to do?


Thanks,
Kim