I am a newbie...and an old gal so please bear with me if I dont explain things quite clearly or if I am in the wrong forum forgive me

...I downloaded an (MPEG/mpg?) video from Limewire. The file Icon says MPEG and the file name says .mpg and clicked on launch which took me to my windows media player...and got the message "Windows Media Player cannot play the file. The Player might not support the file type or might not support the codec that was used to compress the file."...Soooo I tried to open the file with my DivX player and got the message..."This file does not appear to contain a video track"..I know there is data in the video because when I right click it and choose properties...it says 4.02 MB..I downloaded the most current version of Quicktime 7.0 and the video WILL PLAY but then all other facets of my internet and video play options get all screwed up...all I see is a GIANT BLUE Q on the screen where the video should be...Ive downloaded all kinds of codecs (whilst not knowing what the heck a codec is) and the problem persists...when I uninstall Quicktime all other video and internet options begin operating properly but I cant play the Limewire downloaded video...very frustrated here...any ideas...any help? All ideas would be greatly appreciated ...thanks all!