Yesterday while working on my PC my all the devices suddenly got disconnected and when I removed them and inserted them back I got USB device not recognized error in Windows 7, it had also appeared Windows XP earlier. I tried to change the ports but nothing happened. I went into Windows registry and tried to tweak settings there but no success. I read somewhere that in this condition one should reinstall device drivers and then try again, following the same I reinstalled device driver of my USB modem and then pluged it back but I was still getting USB device not recognized error.
I searched on Google about the solution and then I was recommended to uninstall device from Device Manager, I did the same and restarted PC but error still didn't got away.
After getting tired of all this, I finally got the solution and it's the easiest solution which I every came too, you must be too amazed to know about super simple solution to fix USB device not recognized error in Windows.
To fix USB device not recognized error just unplug your computer from main power board and then plug back the computer to power supply. You must be thinking that by Unplug I mean turning off the computer ? Well, unplug here doesn't mean turning off the computer instead you have to first shutdown your computer then remove power cord from power supply and keep it in condition for few minutes and then plug it back and restart your computer and plug in your USB device and it will start working again.
Wondering How did it work ?
Since your computer(or laptop) is connected with UPS(or battery), it has small amount of power going in it even though it is off. Sometimes some circuitry error may disable some functions such as USB recognizing and you get USB device not recognized error or similar feature. Unplugging turn offs the power supply and your computer gets a 'chance' to load all the drivers again and there you go, the problem get's fixed!