Webcam surveyor help

hi, i need some help... i have installed webcam surveyor. on the first time, i is functioning very well. but last night when i plan to use this application, i received an error saying CANNOT CONNECT TO MY CAMERA. THE DEVICE IS ALREADY USED IN OTHERE APPLICATION. PLEASE CLOSE THE APPLICATION WHICH USES THIS VIDEO DEVICE AND RESTART WEBCAM SURVEYOR... that was the problem. but, i really dont have any open program. i tried to unstall and install the software, but still i've got the same error. what will i do?