unity registration bug

Hello!

I downloaded unity 3d about 2 days ago and installed it/registered it via internet. Everything worked out fine, I could start the test game(Angry Bots). Though I wanted to re-install the game in another folder. So I re-installed the game, and when it was time for registration the installer skipped the menu where you choose registration options and whent directly to the confirmation page, where i could press Finish without any registration done. But the game didn't start. And now that happens everytime I try to run the game. I've tried cleansing my computer from every Unity file there is and erased all cache/cookies on the web browser and then tried to re-install. But same error keeps popping up.

Can you please help me solve this problem?

Regards Robert Carlsson