installer.

From Middle French, from Medieval Latin īnstallāre (“to install, put in place, establish”), from in- + stallum (“stall”), from Frankish *stall (“stall, position, place”), from Proto-Germanic *stallaz (“place, position”), from Proto-Indo-European *stel- (“to place, put, post, stand, be rigid”). Cognate with Old High German stal (“location, stall”), Old English steall (“position, stall”), Old English onstellan (“to institute, create, originate, establish, give the example of”), Middle High German anstalt (“institute”), German anstellen (“to conduct, employ”), German einstellen (“to set, adjust, position”), Dutch aanstellen (“to appoint, commission, institute”), Dutch instellen (“to set up, establish”). More at on, stall.