Age Of Empires 3 Error

this game still doesnt want to work on my system,
i have downloaded and installed this codec, and still keep getting the same
error.
ive had this problem since the beta 2 release of vista.
details of error are below.....

the fraunhofer iis mpeg layer 3 codec (13codecx.ax) can not be found on this
computer.
it is a required component of microsoft directshoow, and is required for
proper sound playback in age of empires 3.
please quit out and reinstall this codec befor continuing.
if you choose to continue, an alternative audio coodec may be used which may
cause problems including choppy sound, missing sound, delayed sound and
possible game crashes.


3 gig p4
865 pearl mother board
80 gig hard drive
1 gig ram
nvidia 5x5200
audigy card