playing podcasts

I used to play podcasts (mp3) on quick time. Without warning, windows media
player started playing these files. I tried to change it back but was not
successful. I have gone into the programs checking off boxes in the program
help menus, looked at the program access and defaults. QuickTime asked me if
I wanted to switch files back. I said yes. Now, I can't play the podcasts at
all. Windows media still comes up when I want to play a file but now I get an
error mesage: C00D11B3: Encountered a network error. I get this when I am
connected to the Internet.

I have no idea what to do. I'd like Quick Time back but if it has to be
Windows Media player, I need to know what to do so I can listen to the
podcasts.
Thank you.
Saxon