Internet shuts down when plugging iphone

When i plug the iphone with usb to the computer, the internet shuts down. The internet is wifi, the iphone is 4s and the operating system is win7. I cant even use itunes because when i connect the iphone to the computer the internet shuts down and the connection is lost. Does any one have this problem too? By internet i mean the computer's internet.

Does disconnecting the iPhone immediately restore the wifi connection? Can you it the iPhone into airplane mode and the connect and see if the Internet connection goes down? It's possible there's some sort of interference with your computer..has this always happened or something recent?

This only happens to my phone. When my friend connects her iphone everything works fine. The internet shuts down for few hours..

Does airplane mode help? Does your phone do it to other computers?