If all keys are lost, it is important to take the necessary steps to ensure your safety and security. First, contact a locksmith to have the locks changed on any doors or windows that may be accessible with the lost keys. Next, make sure to update any key cards or key fobs associated with the property. Finally, if you have an alarm system installed, reset all passwords and codes associated with it. Taking these precautions will help protect your home or business from potential theft or other security risks.