If anyone else has this problem:
i just redownloaded and reinstalled and (since four is the lucky time ^^) this time it worked
the only thing i did differently from the three times before is
once sins was finished downloading (while it was veryfying it) o went offline and shiut down my firewall
it installed i tried to start it and it worked
the i started my firewall again downloaded entrenchment and while it was veryfing i went again offline and shut down the firewall and almost magically (^^) it worked too.
thanks to anyone who helped along the way and hope this helps you if you encounter the same problem
now off playing some sins, finally ^^