Sigh, I reinstalled it like 4 or 5 times now. Even with the new 6.0.1119 version. I also deleted everything related to avast with regedit in the safe mode. Again, avast asks for a password after a clean install of Internet Security. When I went back to safe mode after the clean install I could access the avast settings but could not change anything (like it was corrupted and you can’t turn off the self defense). I tried to turn off the password protection in the safe but it would not let me.
The reseller support could not help me so far, so if anyone knows an anwser, it would be nice.