Give some more info:* What version of Ubuntu?* Does internet work at all? (can you browse web)Open Settings->Administration->Software Sources and change the drop down that says "Mirror for India" to "Main server" then close it, it will try to update then you can retry installing mp3 player like VLC...To install VLC open Synaptic Package Manager in Settings->Adminstration menu then search for "vlc" (lowercase) and check the box in front then click "apply" to actually install it.If network/internet connectivity problems, then you need to tackle that first...