Direction of type of desktop display system jig? (8)
I believe the answer is:
guidance
'direction' is the definition.
(guidance is a kind of direction)
'type of desktop display system jig?' is the wordplay.
'type of desktop display system' becomes 'gui' (abbreviation for graphical user interface).
'jig?' becomes 'dance' (jig is a kind of dance).
'gui'+'dance'='GUIDANCE'
'of' acts as a link.
(Other definitions for guidance that I've seen before include "Help in choice of action" , "Direction or advice" , "Advice, assistance" , "instruction" , "Missile component" .)