Since you're a fellow IT guy, I'll assume you've made the sensible choice to not install in program files since win7 is overprotective of it even with UAC disabled. Presumably you've also removed and reinstalled it and since you've not mentioned mods, I take it you're running the vanilla game
Is your system multihomed? 2 NICs might confuse it
Are you dual stacking with ipv6?
Got any weird networking protocols installed?
Done any network tweaks (either manually or with TweakXP, TCPoptimiser)?
There are rare instances that I've seen (mostly with xp) where the windows firewall has flat out lied, saying its not on when it really is, adding an exception for BGmain might still be worth a go, if it works its good and if not its a few bytes of redundant data.
The Baldur.ini file in the install folder has a multiplayer section at the end, it should look similar to this:
Last Protocol Used=2
Manually editing the protocol used entry might be worth a go, 2 is tcp/ip
If you temporarily disable the ip protocol stack, that would help eliminate a connection issue. When you click the multiplayer button, it'd presumably start scanning for available protocols and if there's a problem there, it could get stuck in an endless loop. I'll grant that its unlikely to help but it'd eliminate the protocol as the problem.
Vanilla, yes. No IP6, No dual NIC's, all common network protocols (no virtual adapters either)
Baldur.ini checks out, sorry for the cocky response earlier just frustrated - really wanted to play multiplayer with my wife. Trying to suck her into my nostalgia :(
LordCinnamon - you win the day good sir! The last time I fired up this game was on my compaq persario circa high school, good thing to know for when GoG launches BG2! Thanks!