Automatic Update vs. Standby

I have recently installed several WindowsXP boxes. All are set to run
updates at 3:AM.

Daily users are standard users - an admin user does not log in on a
regular basis. Users log out and the computers are set to go into
standby at the end of the day.

Questions:

Will Auto Update wake a computer from standby (or even hibernation) to
run?

With users logged out, will the computer reboot if necessary? What if
someone is still logged in? If it can't reboot, what does happen?

What happens if an EULA needs to be acknowledged?

Thanks,

T.