Broken window locks can be a serious safety hazard. When locks are not functional, it is much easier for an unwanted visitor to enter the house or for a child to pinch his fingers in--or even fall out of--a window. The best approach to dealing with a broken window lock is to replace it with a new one. Window locks can be purchased at your local hardware store or ordered online.
Remove both pieces of the broken lock. Locks are held onto the window with screws. Use a screwdriver to remove the screws from the lock pieces. It is best to replace the entire lock instead of just the broken half. This will allow the lock to work as well as possible.
Close the window tightly. Put the new lock in the locked position and place it on the window where the old lock was. Replace the screws and tighten them to hold the new lock in place.
Test the lock. Unlock the window and lift or slide it open. Close the window and make sure the lock easily can be relocked.
There are a variety of window locks. However, they are all attached to the window or moulding with screws. This makes installation similar no matter what type of lock you have purchased. If you have a window that slides back and forth to open, you may need to replace the lock with the window open.