Is this only in Skype, or is it on any application that uses the webcam?
If it's just in Skype, try uninstalling Skype then reinstalling it. If it's still acting up, try disabling it, then enabling it again. You can do this by going into the Control Panel and clicking on 'Hardware and Sound.
'
Then, click on 'Device Manager.' (
make sure you are an administrator!!!) Find the section that says 'Imaging devices,' and click the little arrow beside it. Find the name of your webcam and right-click it. You should see a drop-down menu. Click 'Disable,' then click 'Yes.' Your webcam is now disabled. Right-click it again and repeat to enable it again.
You webcam should be working again! (Well, it helped me get my webcam to work again!) If this doesn't work, check for driver updates. If it still isn't working, contact Sony's customer support for help. And if
they can't help, consider picking up a cheap webcam from Wal-Mart or somewhere. Hope I helped!