Errors with videos in gallery

I get an error message when trying to watch every video so far that I have tried to download from the gallery. The video will play for a short time just fine, sometimes upwards of a minute or two. Then it stops playing and I get this message:

Windows Media Player cannot play the file because it is corrupted

These are the only video clips that I have ever had a problem with on my machine. Any thoughts?
having same problems