Hi Again.
Thanks guys for your answers but:
studiodaz: I have try to download the update 5-6 times and even try to download it on a diffrent computer and import it via USB-stick, just to make shure there is not prob. with a firewall or something.
emotive: If there were any probs. with eLc, wouldn´t C7 7.0.0 run at all? It runs with no probs. My Video drivers shall I update/ reinstall as soon i get to the Studio tonight.
I really appreciate your tips anyway because Im totally empty of ideas now.
If your in the neighbourhood, watch out, because tonight maybe a Computer flying through my Studio-window! 
/Matt