@thiloh you have had the worst luck ever.
The “application error” issue is actually a bug with windows 8/8.1. Everything works fine on other OSs.
The issue started with Spotify 1.0.62 which was released to the masses this week.
Edited: removed outdated instructions.
About your corp firewall, that is not a problem, and you have a PM already asking for your HWID to generate a key.