Actually web cam work automatically in win 7 when you need. Like, in skype, yahoo massenger etc. Win 7 has built-in driver for web cam.
You can search in dell website for drive
But if win 7 cant give driver for cam, then you can use update driver from from web cam properties. Type device manager in start menu> then select imaging device> then properties> from driver select update driver> then search in internet. This will do it.
My Name is Ashish and I work for Social Media and Community at Dell. To download the drivers for webcam, please click on the following link: http://bit.ly/fidLPi
Then create your account there. When you finish with the account creation process, it will give you the drivers list and will also have the webcam drivers.