Usb device not recognized problem

This Error Can be possible due to these reasons.

1.Your pc's usb port may not working properly.
2.your phone's data cable is not supported by your pc.
3.your windows's usb drivers are corrupted.

Here are possible solutions.

1.Try Connecting data cable to another usb port.
2. Try changing cable.
3.Try uninstalling usb drivers.
Click Start, then type device manager in the Search box, then click Device Manager.
Expand Universal Serial Bus controllers. Right click a device and click Uninstall. Repeat for each device.
Once complete, restart your computer. Your USB controllers will automatically install.

Read more: http://www.euask.com/topic/6185-My-phone-and-the-computer-automatically-disconnected