I'm running Win7 and was having the dreaded CTD or CTM or just a plain Net7Proxy or Client termination error every few gates or so. But I read a post on here a while back that was very helpful...Forget which one it was but essentially just run the E&BConfig.exe and the net7config.exe as Adminstrator, get your settings right. I have yet to have a CTD since!
Also, if I ever have connection problems, like resets etc. Try running without Packet Optimization(Enable using /packetopt on in game instead) and use the Client Detours. That is all with Multiplayer(Custom) This game is still as touchy as it was in live lol. Just gotta give it a little finesse sometimes.