Squeek when window goes down.

I assume its much stuck somewhere, but when I put the drivers side window down it makes a terrible sqeaking noise. It goes right through me and I imagine its going to scratch the window?

I can't find the offending foreign item so what do I do?
 
i had something similar and cleaned the glass inside and out and has been fine since :001_unsure:
 
my drivers side sometimes does this, also sometimes when i flick it to auto close it goes half way up and then comes back down again, hasn't done it recently