I have a windows XP machine that I can't change the system time. It gives me the following error: "You do not have proper privilege to change the system time

To change the System Time in the Control Panel's System option, you must be logged onto the Windows 2000 workstation as an administrator or as a user who has been granted permission to change this setting.

Log on as an administrator or as a user who has the necessary permissions, and try again

See if this helps


Control Panel --> Administrative Tools --> Local Security Policy -->
Security Settings --> Local Policy --> User Rights Assignment

See if Administrators has the right to change system time.