i have just noticed that aoe 2 runs at about 40-50 fps in all multiplayer games. this is regardless of computer specs or whether i am play lan or on voobly. Me friends allays get 40-50 fps and yet we get 300+ in single player. any advice?

Hello welcome to tech support,
In an online multiplayer game, voobly must connect to the other players and depending on your and their internet connections, locations etc there will always be some sort of lagg which reduces the fps.( even in lan there is that networking going on under the hood).
In singleplayer its just you vs the computer and the cpu ,ram and vga only has to process that ,it does not have to also process the online connection to those other players.
50fps is pretty good to play a 2d game your slowdown is from the other players connections and yours.
I suggest close all programs that use the internet like streaming, downloads, videos while playing and any intensive cpu programs and make sure the game is allowed in the windows firewall as well.

Hope this helps.