We want to start one application (exe file) on start up running as administrator so that users cannot kill it. Is this possible in windows xp
a) Start the application as a service. On Win-Xp the Services can show at least TrayIcons, I'm not sure about windows/forms.
To easily turn any application into a service, you can use srvany from the Windows 2003 Server Ressource Kit.
b) The Windows Task Sheduler is capable of running applications as different users incl. admins (using this method, no windows will be shown).
c) You can run at hh:mm /INTERACTIVE cmd
to start a process as SYSTEM-User
which can interact with the users desktop.