WebCam Monitor continously examines live video frames to detect motion. To reduce the CPU usage, you can try these things:
1. Change the camera settings to use a lower dimension (320 x 240 pixels or lower)
2. Lower the frame rate if your camera supports this feature
For WebCam and DV Cameras, you can change these settings from Camera Properties and Video Properties available under the File menu.
For IP Cameras, you can change these settings from the Tools ] Options ] IP Camera tab. From the IP Camera tab, select the camera for which you want to change the settings and click Edit.