I sometimes have to work using computers whose clocks are off by several hours and would like to have more precise time without needing system operator rights. Is there a clock for the windows system tray that uses NTP or so instead of relying on the system time and that I can just put into my autorun folder?
The best solution is to configure the Windows NTP client as described in this TechNet article. That way, every application on your machine (including the system tray clock) will know the correct time.
UPDATE: I missed the part in the question where the poster says he doesn't have administrator rights. NTP Clock is a free clock app for Windows (though it doesn't run in the system tray) that can directly query NTP servers.