Inspect the locking devices on all the windows in your home. Replace non-working, worn, or faulty hardware. Add security to sliding windows by placing a length of wood or broom handle in each track. Close and lock all windows whenever you leave your home, even if for a short time.
Install laminated film on your home's windows. The film will strengthen the glass and make it nearly impossible to break or shatter.
Install metal bars on the windows to make them burglar-proof. Even if a crook manages to break the glass, he won't be able to get past the bars.
Replace the glass in the windows with reinforced glass. Choose bullet-proof glass, glass that's reinforced with wire, tempered glass like that in autos, laminated glass that has a layer of plastic inside or Plexiglass, which is highly resistant to impact.