I have enabled the GPO settings in Windows Server 2003 to automatically download and install Windows Updates for my XP clients at a set scheduled time. I have the option to apply these updates and automatically rebooting the XP computer after a countdown of five minutes, or waiting for a user to log off. I prefer the forced reboot after countdown method because if a non-administrator is logged into one of these XP clients, they can't cancel the update and must log off to allow for the updates to begin. I will set this schedule at an appropriate time in the wee hours of the morning.
As a result, I would like to send out to all the networked XP clients one of those little yellow balloon messenger popup alerts that appear in the system tray (or perhaps one of those Net Send gray standard WinPop type message dialogs) that remind users that their computer will be automatically rebooted at a set time and should be shutdown. This is to prevent people who typically leave their computers on all day and night during the week to remember to log off on Friday evening, for example, since updates will be applied on the weekend.
Can this be done with Alerter or Messenger services, perhaps in combination with Scheduled Tasks or other built-in utility? I'm sure there are millions of third-party utilities that will allow me to do this, but I'm looking for a Microsoft tool, feature, utility or GPO setting that will accomplish this.
Thanks in advance.