Please Help! Can't play Quick Time media!

[kkn0113]

I have downloaded both Quick Time and WMP files. The WMP ones run great! (played on my WMP) But any of the ones that are Quick Time won't play on my Quick Time player. So I tried going in and switching them to run on WMP, but when I actually try to play them, I get an error message saying that the file is not formatted correctly to play on WMP! Does this mean that I am stuck only being able to download WMP files? Because there are several files I want that are not WMP files. What do I do? Can I do anything? Someone please help me! I've been messing with this for hours and I'm getting frustrated! Thank you for your help!