You should always be able to obtain the latest version on your account page, thereby eliminating the need for a product key. The account page is set up the very first time you register a product.
For your area I think the UK is th eappropriate one: http://home.mcafee.com/Default.aspx?culture=EN-GB
Click on the link at top right.
Were you able to find your products under your account page and reinstall them successfully ????