Windows possibly get obscured or panes get misty (9,6)
I believe the answer is:
operating system
'windows possibly' is the definition.
'get obscured or panes get misty' is the wordplay.
'get obscured' is an anagram indicator.
'or'+'panes'+'get'+'misty'='orpanesgetmisty'
'orpanesgetmisty' is an anagram of 'OPERATING SYSTEM'.
(Other definitions for operating system that I've seen before include "Software providing a computer's basic functions" , "Essential software" , "surgical procedure?" , "MO?" , "Essential computer facility" .)