unable to connect to any environment

unable to connect to any environment

I am having problems connecting Service Studio v to both my personal and enterprise OS environment.
The error I am getting is: Host not found. From another ( windows8.1) pc in the same network everything works fine. I am running Windows 7. 

So far we tried to open all outgoing ports, disabling the firewall and virus scanner, flush DNS and reinstalling Service Studio.

Any ideas what can be wrong?

Thanks in advance
You tried the right options I think...
In the header of the error message you have "Comunication error"? and the message is "There was as error contacting ... ... : Host not found".?

By any chance, do you have any proxy connection configured on that machine?
I have solved the issue. We found a (hidden) proxy connection that was blocking the port.
It seemed we had disabled all proxy settings, but apparently there was still one active on the background.

Thank you all for your replies and advice.