wanted to replace these icons with a new one. which files contains these icons? i looked in the shell32.dll but.......cant find. any bit of information would be very helpful. thanks

The easiest way to do this is to get IconPackager from StarDock.

Otherwise, you have to dig in the registry for what you want. For each file extension, you have to select the file where the icon is located.

does anyone know which file contain these icons? thanks

wmplayer.exe holds THE ICON associated to all those extensions, so there is no one icon per each file type. You must play with the registry in order to change the icon for each of the file type. With WMP11 I think that this has changed, but not really sure.