- How to play Heroes 3 online.

It's not possible to play with Windows XP when one player is on Windows 7. We usually play Windows 7 vs. Windows 7, and the connection works perfectly. We even tried 1v1 with two Windows 7 machines, and it worked fine. But with Windows XP, there's no connection... We're playing through Hamachi.

First, have the friend with Windows XP be the server – this will reduce problems.
Second, if the firewall is disabled and the server still isn't visible, you can look for firewalls in the modem; they are almost always there.
Disable any antivirus programs – this can also interfere with the game.

Neither of these helped. Both of us have dedicated internet connections.

If nothing works, I suggest trying Windows XP with Windows XP, even if it's just on a virtual machine; this will increase the chances of success...

I have four friends, not counting myself, all using Windows 7. They all have to set up virtual machines to play over the network with Windows XP... Well, if there's no other way, I guess we'll have to.

I don't know if it's possible to install IPX on Windows 7, but if it is, I suggest trying that too.

I haven't found anything useful about this online... It seems like it's not possible yet, although maybe I didn't search well, and I'm not very good at English.

Question.
If I have one account for an address, and two PCs are connected to the network through a router, can they play against each other in TCP/IP?

Yes, we played that way