Hi Amitdv6500,
Welcome to the HP Forums!
I would like to take a moment and thank you for using the forum, it is a great place to find answers. For you to have the best experience in the HP forum, I would like to direct your attention to the HP Forums Guide First Time Here? Learn How to Post and More.
I grasp that you upgraded your system to Windows 7 and HP does not list drivers for it. When there are no drivers listed for your operating system and your notebook, it simply means that HP has not tested it on your model. You will need to locate any missing drivers yourself. Here is a link to documentation to assist you. Downloading or Updating Software and Drivers for HP Computers.