Abstract: Disclosed herein are improvements for sash windows including a system which can be used with a variety of balancing systems which comprises a jamb liner being mountable in a window jamb for guiding a pair of sliding sashs, the jamb liner having a longitudinal body, the body having a front face configured such that a side of the sashs is slidably and engageably mountable thereto, and an oppositely facing rear face mountable to a recess in a side of the jamb, wherein the rear face of the body is configured such that the jamb liner is securely receivable by the recess and removable therefrom. Further disclosed is a window system having a jamb liner and a pulley device.