Reinstall Adobe CS Master Edition (lost key)

Hey I had to reinstall my windows on my laptop a couple of days ago because I had caught a virus.

I have wiped my entire C: disc and also my complete Adobe CS Master Edition that I need for my schoolwork, since I study Game Development.

Now I need to reinstall my Master Edition, but I have lost the key. I bought via my school, who used a reseller for this, named Signpost.

How can I download my Adobe product again?

Thanks in advance.