Struggles in playing AoC in LAN

I organized a LAN party, where we would play AoC. I tried it on two seperate systems and it worked (both were win7). But then a friend with a win10 PC came in. We did everything the same, tried mulitiple settings, compatibility with multiple earlier windows versions, allowed AoC through the firewall, still nothing so far from any win10 pc's. Any help appreciated!