[Angrist]

I went to the store. The guy seemed very pessimistic about the whole thing.

He advised me to reinstall Windows and see if the problem persists. I guess I'll try that after I've tried some other, smaller things.
Like I changed my firewall settings a few weeks ago, now I discovered Windows hasn't been able to update. So I'm going to change that and see if it makes a difference.
The firewall also blocks a lot of other stuff, I wonder if it is to blame...