Error Messase for Media Files

[smilinjack]

Greetings and thanks in advance for all who help!
Suddenly when I double click on a .Mp3 file I get:
"Filename.Mp3 access is denied".
This was preceeded by a menu opening asking which program I wanted to use to
open the file. When I choose Media player after getting the "Open With" Dialog box and
then checked:
"Always use the selected program to open this file",
It ignored that and I hade to repeat the same proceedure every time.
Formally, It was just a matter of doulble clicking the file.

Thank You,
Jack