Lost external drive upon reboot

This is the first time this has happened and I find it odd. I rebooted the PC after a protected session and one of the 2 external USB drives I had connected to the PC at the time showed up as new hardware. Supposedly the drivers were loaded but the drive was not recognized. Turned the drive off and then on and got a message that there was a problem with the drive and to troubleshoot to do xyz (etc). I tried rebooting and again the drive was not recognized. Rebooted again and the drive was back.

Any idea why this may have happened? Should I be dismounting all external drives when I go into a protected state? I close all apps (other than anti-virus etc) as instructed but it never occurred to me that perhaps I should be doing the same with drives as well.

 

Thats a fluke with the operating system (XP).

Wi-Fi USB's also do that every so often.

It's all in the way that XP loads each device as it's booting.
If one happens to get out of order, thats what you get.
eg: "Windows could not load device drivers for this device" yada yada

Sometimes they get confused!

Frustrating, but nothing to worry about.

 

Thanks tekie, much appreciated.