Video Site Monitor (Free Version)

From the developer: ""The 'Free Version' provides basic video motion detection and issues selectable sound alarms. Video Motion Detection, Source, and Format parameters are setable. Detection can be calibrated. Live Video Window and Motion Detected Windows shown. Look outside from inside. You can record and play your own audible alarms e.g. 'a customer has entered the store' or 'intruder alert'. Good for watching over the backyard, front door, inner rooms.""

Requirements:

Windows 95/98/Me/NT/2000/XP, camera