After instalation wn7 my camera webcam us not fonctionaly

go to the manufacturer's website and see if they have drivers for your web cam.

Many oldr webcams (and scanners) that worked with XP do not work with the newer Windows Vista/7/8 driver model, and because they want to sell you a new camera, they never bothered making a new model for the newer OS's.

If it is a newer model then I would suggest talking with whoever sold it to you, or directly with the manufacturer as one or the other should be able to get you some help or a replacement.