Upgrading from Flashbuilder 4.0 to 4.7

[nameadobeforcedmetocreate]

I have been attempting to apply this upgrade for days and have yet to get anywhere. I have a valid key for Flashbuilder 4 premium, but when I try to register, it says it can't find a copy of the application on my computer, so when I tried to go and open my current version of Flashbuilder 4.0 and the application won't open. I'm 99.99999999999% positive that has nothing to do with my attempts at installing 4.7, but now I'm stuck with a broken application that is registered and a working application that is being used on a trial basis. I think that re-installing 4.0 and then attempting to install the upgrade would fix the problem I'm having, but can't find a working download for installing 4.0.

[nameadobeforcedmetocreate]

Sorry, meant to mention that both 4.0 and 4.7 versions are premium.