Problem Launching Mtw

well I'm new here and not sure if this is the correct place to post this
oh well
I reinstalled MTW after a couple of months and find with the damn surprise that the game freezes each time I try to run it,don't know why I installed it correctly,disc is ok and everything in my PC is ok
what I've been wondering is that lately I downloaded a damn codec for playing some torrents I downloaded (x264) or some sh*t like that
is there any chance that the nw codec intefere with the game when it runs?
cuz if so XD I'm doomed
any ways,what can I do to play total war again,I even tried with a nocd and it's just the smae :o thanks