The Design Center has two separate systems: a Unix system and a Windows NT system. Although users have the same username on the two systems, the passwords are separate.
It will ask for your old password. Enter it. Then it will ask for your new password. Enter your new selection for a password. Your password must be 5-8 characters long and contain at least one special character (a number or a printable non-alpha-numberic character) or multiple case (passwords are case sensitive, so pay attention to the case). Then it will ask you to enter it again to make sure.
If you entered your old password properly and your new password fits the specification(s), your password will be changed. Please remember your password for all future logins.
Ctrl-Alt-Deland choose the password change button from the dialog that appears.