Here are some ways to do this.
1. Double click on the clock in your systray. This will bring up the
Date / Time properties dialog box. You can adjust the system time from here.
2. Go to the control panel and click on the icon that says Date / Time,
this will also bring up the Date / Time properties dialog box.
3. From a command prompt type
NET TIME \\TIMESRV /SET /YES
For more on this see KB article
http://support.microsoft.com/kb/120944/EN-US/
4. Change the time in the BIOS.
Now I don't intend to sound like a jerk but,
How in the HELL did you get a sysadmin job and not know how to change
the Freak’n system time. I’d really like to know because I’m just a
desktop support guy and I would like to move up to the server world.
Dave