You can change settings of wmp to only be associated with files you want it to open,other way is right click on a file & use open with, you may or may not be given option to make it the default to open those files in future,again you can set file type associations by whatever program you want to open those particular files by using that particular programs settings,so for videos i have vlc as the default,for pictures i have set FastStone as default to open pictures,for iso files it's imgburn or i use open with
