Soldato
Changing the icon in Properties has no effect.
Have you tried rebuilding the icon cache (if you're using Vista)?
Launch an elevated CMD window, ie Right click, Run as Administrator...
Shutdown Explorer Process from the Task Manager
In the CMD window go to C:\Users\<ProfileName>\AppData\Local
Do the following command: attrib -H IconCache.db
Do the following command: del IconCache.db
Do the following command: start explorer