Some Nokia Lumia or windows phone users have been facing the USB connectivity problem where they connect their phone to the computer and driver installation fails. This happens when your computer fails to provide MTP drivers for it. MTP is the protocol via which your device and PC talks so we must get those drivers installed so that they are able to talk to each other.
1 go to device manager
2 right click on device and choose update driver
3 choose browse computer for driver software.
4 choose let me pick from a list of device drivers on my computer.
5 choose portable devices and then select standard MTP device
6 choose MTP USB device and then click next. Your nokia lumia or any other WP device will be installed.
Now you go to My Computer and transfer files to and fro from phone and PC.