My camera cannot function what could i do - A4tech PK-635 Webcam

Hi,
you need driver to use your webcam,if you are using win 7 os your older driver is not compatible
click here
(http://www.a4tech.com/driver/A4%20PC%20Camera%20H.rar)
to download driver for your web cam (win 7 compatibility) from official site of A4tech.
since it is rar file you need software like 7zip or winrar
follow the instructions below for proper installation

• Save driver somewhere where you will remember after download . i recommend that you save it on your desktop , so it will be easy to find .
• After successfully downloading the driver , do not open the driver file until you make sure the following has completed : ***REMOVE / UNINSTALL any webcam driver from the PC . ( If you forgot to do this part , your driver may not be able to install correctly and successfully later )
• After the original driver has been removed , open the downloaded file
  
• Follow the on-screen instructions .
• When it's successfully installed , please restart your computer .
  
• After you have restarted the computer , plug the webcam into your computer and it will automatically recognize the new hardware.