iMovie '09 Register help

I did a clean install of Snow Leopard recently and also wanted to do a clean install of iLife '09 (both came with macbook) and when i finished installing iLife, none of the products would work and told me I needed to register them to be able to use them. When I tryed to register them it asked for a MPN and told me where to find it, after looking for it for about 2 hours, I gave up and came here. I need some one to tell me how, and if, I can to register my iLife products.

Thanks!