What's the deal with windows store certificates?

I was wondering about certificates when exporting to windows store. I go to player settings, certificate and then click on create bar. A metrotestcertificate pops up in the project pane. When I use visual studio to export, it gives and error on this certificate. Everything else seems fine.

So I am assuming there needs to be some valid certificate or something to use for the game? I'm sure this has come up before but can't figure it out. Thanks.