Steps to reset password in server 2003
Click Start, highlight "Administrative Tools" and select "Active Directory Users and Computers"
In the console tree, click Users.
In the details pane, right-click the user whose password you want to reset, and then click Reset Password.
Type and confirm the password.
If you want to require the user to change this password at the next logon process, select the User must change password at next logon check box.