USB - unplug and play ?

Some strange things happened recently. I'd been taking a backup of my desktop's hard disk drives using my Seagate external drive because I thought I might need to attempt to recover a file from an earlier backup and safe is better than sorry. 

But I didn't quite get around to it on the first day, nor the second. Eventually I noticed messages saying something like "unable to save on J:\$mt".  

A while later, after rebooting the machine, things stopped working big time. I had another external hard disk drive (Freecom HDD) on which I had my backup versions of  Apache, MySQL, WordPress, Drupal and static sites. PLUS all my music. I'd never got about to finding space within the box. BUT the machine refused to accept the drive. It just said "Unknown device - device not recognised". 

I unplugged it from one USB port and tried another. No luck. I unplugged all the other USB devices (even the keyboard which was a bit silly) but still no luck. Then I noticed that my desktop refused to acknowledge my HP Photosmart printer.

Well I went into damage limitation / recovery mode.

1. Tried system restore. Nothing.
2. Tried an earlier date. Nothing
3. So I had to make it work the hard way... I copied all required files from the Freecom drive to the desktop's internal disks using FTP from my laptop.
4. Reconfigured the internal drive's letter to become what was the external drive's letter 
5. Rebooted and got my local webserver working again
6. So I was partially happy but the USB devices still didn't work.
7. Reinstalled HP drivers. Nothing.
8. Fiddled about with the registry. Nothing.
9. Hunted on the internet. 
10. Lo and behold I found a story from someone who had something similar. His solution. 

TURN THE MACHINE OFF AND UNPLUG IT. 

A b*gg*r me if it didn't work. 

So the moral of the story is...

If your USB plug and play device stops working you should UNPLUG rather than play.

And the other good thing that came from all this effort is that my desktop is much tidier. And I now only rely on the Freecom drive for the music.