problem with xbox

i keep getting this screen saying the disc cannot be read it may be scratched or damaged. im not sure its the game because i just bought it (fable-the lost chapters) and when i first played it that screen came up and it keeps coming up. it could be my xbox. i was watching a dvd and it kept freezing then i watched it at my friends and it didn't. and sometimes my xbox mistakes xbox game for dvds and says i need the dvd playback kit to play this dvd?
any suggestions how to fix this?
-now my xbox is making a loud humming noise when i play a game(just unmodded it and deleted mod files) this has never happened before when i'v done this
-still having dirty disc error

 

if u want to try opening up ur xbox and use rubbing alchol and q-tip to clean the disc lens

 

how do i open it up safely and put it back together, i'v never done that before?

 

just get a laser lense cleaner and pop that in there and that should fix the prob the disk is only like $6 at any gaming store

just make sure its for the Xbox console mkay

 

thanks

 

no prob same thing happened to me

 

just dont use it too many times or it will scratch the lense mkay