I suggest you repeat the drivers you installed the first time. Or use system restore to go back to when it worked.
Hello, so I bought this new Dell inpiron n5521 laptop on 5th april. It was working fine and the camera was flawless without any lag or errors.
After a week, when I started the Camera app from the Start Screen (It came with ubuntu but I have installed Win8. Yes, it worked with windows 8 in the beginning) it loaded a greyish page saying that a camera was not connected ('camera not found').
I hope that this is a software level problem, and the product is under warranty and I have the Dell Pass.