Technical issues with Heroes III.

Good evening, everyone. Maybe someone can help? I have a basic computer, Windows 7, everything was installed, the Hamachi ping works, but the server doesn't see either me or my opponent. The firewall is disabled, the antivirus is also disabled, and it won't let me join the game, saying it can't find it even when connecting directly via IP. Could there be any additional blocks in Windows 7? Has anyone encountered this or know what to do? Thank you in advance.