after installing ffdshow i cant get windows media to open movie files at all

hi, i recently installed ffdshow because someone told me it would sort out the low framerate problems ive been having with some files. as i installed it i got one error type message but i choose to ginore it and keep on installing. now when i open movies, the screen comes up as if its about to play (no error messages or anything) but the movie doesnt start at all. i can get it to play on divx, but i get no picture, just a bunch of green lines, what can i do to fix this? thanks in advance for any help.

if you’re trying to play xvid files, install Koepi’s XviD Codec
http://www.free-codecs.com/download/Koepi_XviD.htm

I download the movie but dont know where it has been saved in my computer.