Locking the windows before leaving the house deters burglars and provides a homeowner with peace of mind that his property is safe. Locking window latches sometimes become stiff and do not lock properly. Do not force the key. Apply a lubricating spray to the lock and key and try again. If the lock still doesn't work, you may have to take a trip to the local DIY store. A simple window stay-lock, including screws, fittings and keys, is inexpensive and can be fitted in 10 minutes.
Unscrew and remove the existing stay location bracket on the bottom of the window frame.
Screw the new stay location bracket into the sill in place of the old bracket. Most window stay brackets are packaged with a plastic wedge for use on a sloping window frame. The plastic wedge will ensure the stay location bracket sits level on the window sill.
Secure the window stay location bracket by screwing the locking nut in position with the key provided with the lock. The locking nut tightens over the top of the bottom window latch.