D2 will load up and you can connect to server.. what is game breaking is the updating of the D2 map when someone finishes a mission.. delay time for update is up to 2 min and no response from the server or your client to move to a different hex.. thus causing Player Mission matching to crash the client / server since a player on Windows 7 can't update properly.
Wait a minute - only 2 minutes? does it EVENTUALLY load? If that the case you might not be able to play on a REAL D2 server but you won't be left out of our-turn based game if you're into PvP. Will it report the results of a battle and let you move after about 5 minutes?
Yes.. once you get the game to connect to the D2.. game works normally Except the game map when it updates.. as such, it takes up to 2 min for the Windows 7 client to update the map, then the character can move locations or use the loadout options or shipyard.. the problem is that it does this with every map update.. as such.. when the map updates, and you can move, you may be stuck another 2 min before you move again if someone came out of mission before or during your move.
for real time D2 game play, it is a breaker.. if you are using turnbased movement, it is possible to still use the Windows 7 / Vista clients.
In order to connect you have to set the game to Administrator mode and XPSp 3 compatibility, launch game and attempt to connect to Dynaverse.. First attempt will give firewall message.. Alt-F4 out and immediately re-launch the game and then connect to the dynaverse, you will then connect to the directory servers and as such you can log into a D2 server.
You can then move about freely for 3 or 4 hexes and even upgrade ship or load out and even go on a mission before the map updates start lagging out the Vista / Windows 7 client.
So Yes it is possible to use Windows 7 / Vista for a turn based movement system, just not real time D2 Flip the Hex battles.