Ok lets see if we can get you back on the network
What stage of the install did you get up to ?
Did it install ok but fail to connect still ?
Did you have the old winmx closed down when you tried the install ?
What operating system are you using ?
If it installed ok, then check your firewall is allowing it through , you can save a few minutes by taking out any firewall rules that show winmx and then rerunning it so it will ask you if you want to allow winmx through again.
Do you have a router ?
If you do remember to "forward" the ports on it with the same ones you use in winmx.
I hope some of this helps point you in the right direction, and please let us know what help you need and on which section of the setup routine.