Umm...you either mean one of two things.
1 - Transfer the files that aren't playing to another PC, and see if they play there. No, I haven't tried that, but I don't think it would work, seeing as the files show up as WAY smaller KB than they really are, and show they only last a few seconds. (But I'm no computer genius, so I'll have to try that anyways).
2 - Download the files on another PC then transfer them to the one I'm trying to get them to. I don't physically have the permission to use any other computer for long enough to download the files, so at this point this is very impossible.
What I actually think is happening is my computer is literally only downloading part of the file (and a very small part at that) and before now, this hasn't really effected anything I've needed/wanted to do, so I didn't bother to figure it out. But I figure that at this point I need to get the prombem fixed instead of messing with a way to work around the problem at the time being.