A system for supporting a window sash that allows for the removal of the sash from between opposed window jambs. The system supports the window sash through counterbalance shoes supporting sash support arms pivotally attached to the sash. The shoes include hooks which, in first positions, engage lances in the window jambs to hold the shoes in place as the sash is removed from or installed between the window lambs. The hooks, in second positions, engage pins extending from the support arms to retain the support arms on the shoes.