Windows 7, Lan works, no internet, i see others, others cant see me

Hi everybody,

There are a lot of partially similar problems, but non of the solutions i found until now worked for me.

I am trying to connect a new secondhand server with freshly installed windows 7 64.

when i plug the network cable, i see all other computers in the network.
I can ping, them, i can even make a remote desktop connection.

But the other way around it doesnt work.
they cant ping me, they cant see me.

also internet doesnt work on this computer.

The fire wall is switched of, no Bounjour is running, i tried all what i could find in the web (during the last 3 hours).

If there is any one who has a good tip, i would be gratefull.

Thanks