What is the serial key for?

thanks that is why I never had use for it and never will ;)

I already opened a support ticket about this, but it doesn't hurt to ask it here too.

I entered my e-mail and the Serial Key in the respective slots in the Multiplayer -> Settings, but whenever I try, it first stays at "Connecting to Public Server" for a few seconds and then "Cannot connect to Public Server...". How can I play multiplayer, is it broken?

Thanks

Genoan replied and told me to try starting the game choosing Run as Administrator.

I tried it today and it worked. I don't know if it's about the Administrator thing or the server was down at that time.

I can login to the server now. Unfortunately there were only a few people there and none of them responded :)