Skype USB Video Device problem! PLEASE HHEEELP!?

Recently I reinstalled windows on my laptop and now I'm not able to see myself when logging into a skype. I have a laptop Sony VAIO VGN VGN NW 240 F and I tried every possible way for solution and unfortunately it doesnt worked. I even reinstalled my windows again TWICE, but no luck. I downloaded drivers from sony website, I updated DirectX but nothing. whenever Im opening up skype and clicking on the video, black screen shows up which says : can't start video. try closing other programs that might be using you webcam . I have installed 3 or 4 programs so far and its impossible that some of them might use my webcam. Please if someone experienced the same problem let me know how to fix it, I would really appreciate that. Oh and just for the records i have Windows 7 Ultimate (32 bit)