I have a Lenovo Z400 touch labtop and when i first bought it the built in webcam worked fine?

Now on skype or any other program it says attach camera. I've tried reinstalling the drivers and everything but i can't figure it out.

Click "Tools" at the top of the Skype window and select "Options" from the drop-down menu to open the Skype Options window. Click "Video settings" in the left navigation pane to view the video settings in the right pane. Click once on the "Select Webcam" box and select a different webcam source from the drop-down menu it should solve the problem