My name is Ashutosh kumar sharma and i work for social media and community team at Dell.
The issue can be resolved by updating drivers,Follow the steps mentioned below:
1. Click Start.
2. Type Device Manager in Start search.
3. Expand Imaging Devices in device manager window.
4. Right click on the Device.
5. Click on Properties.
6. Click on Driver Tab.
7. Click on Update drivers.
8. Click OK.
If still the issue is not resolved,then uninstall and uninstall the webcam drivers from www.support.dell.com.
You have not mentioned the system model otherwise i would have given you the exact link to download drivers.
Hope this resolves the issue.