I have had similar problems running vista 64 bit. After spending a week with Microsft
trying a zillion different things and nothing working, they told me it was a hardware
issue. The computer would not recognize my thumb drive while all the time I had a USB
external drive that was working fine and was reluctant to unplug it lest it wouldn't
recognize it the nex time I plugged it in, Well the first thing they did was to unplug
the drive! They rebooted the PC and plugged in the thumb drive and it worked fine. They
then plugged in the external drive and that worked fine also. We found out three things
about USB this weekend on my PC. 1. The order in which you plug in the USB items matters.
If the external drive is plugged in it won't recognize the thumb drive, but if the thumb
drive is plugged in first, then the external drive comes up also. We plugged in several
thumb drives and they all worked. 2. If we had both the thumb drive and external drive
plugged in,removing the thumb drive rendered the external drive an "unknown device". 3.
disconnecting power from the device and then powering it up again will make it
recognizable This may have something to do with the fact that the thumb drive is an
unpowered device and the external drive is powered, I just don't know but a couple of
things are clear to me, USP isn't supposed to work this way and Microsoft doesn't
understand how USB works. I don't know if this is an issues only with the 64 bit version
or if it's across the board with Vista. The next time I talk to Microsoft on this
issue, I'll let them know about this, they need all the help they can get!
