Put in position (9)
'put in position' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for installed that I've seen before include "In position ready to use" , "Put in or set up for use" , "Parked" , "Positioned, set up" , "Given office" .)
(Other definitions for situated that I've seen before include "Located; put into position" , "Placed or located in certain position" , "Positioned" .)