Tjeeena! Jag har sökt sen säkert klockan 4 idag och ingenting vägrar fungera, förhoppningsvis är det någon som kanske har haft samma problem och har löst problemet.
Jag skrev på GW's forum, det är därför det får bli på engelska eftersom jag är lat och inte orkar översätta.

Hey!
Today I bought GW2 on sale for the first time, I have never downloaded it before.
I bought the game, wrote down my serial code and I was about to start the client when the client tells me this “Connection error(s) detected. Retrying…”
Things I have done:
- Changed my DNS to 8.8.4.4
- Removed the client and tried again
- Updated a old internet update
- Changed my hosts file in System32
- Restarted my network and waited for 5-6 minutes
- Rebooted my computer
- I waited for 4 hours while I was away
A friend of mine that helped me with those things wanted me to download Teamviewer, the thing was when I opened TW. It clearly said to me "Not ready, Check your network.
So I am guessing it’s something wrong with my internet connection at the moment but the weird thing is that I haven’t noticed that anything is wrong with my internet
connection per se, it’s just something that programs pick up which makes me unable to install GW2, Teamviewer etc.