Iphone does not connect with pc
Are you using the same USB cable and adapter that came with the phone? If yes, did you check the docking port and cable for any kind of debris, lint or bent pins?
Next step would be a reset by holding the sleep and home button for about 10 sec, until the Apple logo comes back again. You will not lose data by resetting.
If still no luck, try to connect in recovery mode, explained in this article:
If you can't update or restore your iOS device
If still not recognized, check this article for more suggestions:
iPhone, iPad, or iPod not recognized in iTunes for Windows - Apple Support