My apologies if this has been covered in another thread. My various searches did not find anything with this solution. Hopefully many will find this more useful than chasing down newer versions of the software that may or may not work.
I had been having the same issue as many others here have had with Webcam Center on Windows 7 suddenly not recognizing the integrated webcam. I was searching all over for a possible solution and finally ran across a forum posting on the Dell website suggesting that all that was needed was to have the Webcam Center program open and to then plug in ANY USB device. I tried this using a basic USB mouse and after a couple of seconds, the webcam magically started working normally. I have no idea what the correlation between the two is, but I am glad that worked so easily. My camera seem to be functioning completely now.