Hello,
Validation requires no validation number. Installation and activating Vista requires product key. If your new computer has Vista as operating system, you should have the COA (please see http://www.microsoft.com/resources/howtotell/en/coa.mspx for info on COA). The COA includes the 25-character product key.
If your Vista has been activated, you need to run validation to take advantage of the benefits of Windows Genuine Advantage Program and to check whether your Vista is authentic.
If validation failed, please download the WGA diagnostic tool from http://go.microsoft.com/fwlink/?linkid=52012. Run the tool. Click 'Continue' and make a reply here to post the log.