i am trying to connect with Radmin 3.0 to my home computer from work. But when I try to do that I always get "unable to connect" message.
But if I use any other network -for example any free wifi or from my friends network- which is connected to the internet, then I have no problems connecting to my home computer (via internet) with Viewer.
Is it possible that network administrators at my work have somehow locked or disabled some ports or something, so I am unable to connect to my home PC via work network?
Is it possible to avoid this 'protection' so I can connect also from work place?
Some firewalls only allow outgoing traffic on authorized ports. You will probably need to ask your network administrator if they can allow you outgoing access on port 4899 (or whatever port your home Radmin server is configured for). Depending on the individual, and the policies they have to go by, they may or may not be willing to allow this.
Assuming that's the mechanism that's blocking you, there's no way that I know of to bypass that with RAdmin. You might be able to bypass it with a web-based service such as GoToMyPC, though I'm not certain of that; and I'm sure you don't really want to start incurring a monthly fee.
I know this is probably not the answer you were hoping for, but I hope it helps anyway.