Lock the keyboard and mouse to stop those wandering little fingers. Child Lock can help you lock the keyboard and mouse so that they arent available for kids.
Can be set to autolock after a period of inactivity - stops little fingers once you have left the PC. Can block out windows control keys - switch out of the current software (provided the app is running fullscreen such as a game). Can slow down the mouse, stop autorepeat - assists young ones just getting used to a mouse and keyboard.

The license of this software is Freeware, you can free download and free use this system locking software.