Users in Windows Server 2003 forgot password and want to reset it. Whether you forgot password or want to modify it, do so by accessing administrative tools. For this you should have administrative access. This is approved to users contained in Domain Admins group or Enterprise Admins group. If you are not in either of these groups, contact the system administrator to grant you administrator permissions.

Instructions
• Go to "Start" and click "Control Panel."
• Choose "Administrative Tools," then "Active Directory Users and Computers" and click "Users."
• Right click username in details pane. Choose "Reset Password."
• Type favored new password and enter it again to verify. After finished, it must save new password.