How to solve "USB device not recognized" problem in Microsoft Windows

Went around to a friend's place earlier tonight to continue reinstalling all his programs, etc. after I put in a new hard drive for him the other day, upgraded his RAM from 512MB to 2GB and installed Windows XP Service Pack 3.

I tried connecting his external hard drive with all his backups, etc. and I kept getting a 'USB device not recognized' message. No matter what I did, I couldn't get it to work. Funny thing is, it worked when I was last there 2 days ago. I tried uninstalling the 'Unknown Device' in Device Manager and rebooted. Nope, still didn't work. I even restored a Ghost image I made the other day (after making a current image), nope, still no go so I restored the current image.

I really began to think his external hard drive had failed when I thought: hmm, I'll try one of my USB flash drives which I know is perfectly fine and... surprise, surprise, I got the 'USB device not recognized' message again.

So, I did a bit of online searching and came across this:

http://ghost301tech.wordpress.com/2009/10/02/how-to-solve-usb-device-not-recognized-problem-in-microsoft-windows/

I shut down Windows normally. Then, I turned the computer off at the wall switch for about a minute. Then, when I started Windows up again, everything worked perfectly.

Now that I think about it, another friend had the same or similar problem about 8 or 9 years back and the solution ended up being to turn the computer off at the wall switch then start it up again.

The same solution can also be applied to laptops. But, in this case, you need to remove the battery for a short time after disconnecting the mains power.

That is weird! Wonder why it happens in the first place?

Might be caused by a power glitch? I suspect something happens that causes insufficient power to be delivered to the USB ports.

Do you remember 'shiny balls'?



I don't use those anymore but, when I did, I couldn't use any of those small, portable USB powered hard drives in them. I would get the same 'USB device not recognized' error message from Windows. My theory is that those USB powered hard drives draw close to the maximum power available from the USB port and with those LED's on the 'balls', the hard drives were trying to draw more power from the USB port than was available.

If I used a normal USB extension cable instead of the 'balls', I didn't have a problem.

Ah, ok that makes sense.