Usb storage hard drive no longer working in xp

It is time to start transferring data to my new build. I have 2 usb storage hard drives, 250gb wd mybook
and a homebuilt 500gb sata wd drive. Both units have worked fine and are working in my new build...
but I was not able to access either in my old computer with windows xp with service pack 3.

The procedure to access the usb hard drive I have used with past years success is: plug in usb cable
to usb port, turn on power. Has always worked before. Both drives do work in new computer with
windows 7 64 bit. After plugging the usb hard drive into the xp computer, the usb icon appears in the
xp comp. but the window does not pop up offering choices for the usb storage drive.
The drive does not show up in windows explorer. I have checked device manager for any "!",
but all seems well. I tried to add new hardware, seems endless loop, system unresponsive.
In general, my system seems to stop working. I have to manually re-boot. I have tried searching
within xp for clues, but none are apparent. I have changed the drive letter of one of the storage hard
drives to 'Y' in case a conflict. I did not help.

I do not want to consider re-installing xp, sure hate to have to remove the old IDE data hard drive on the machine
to place into another old relic with IDE and copy may data files. I had recently had a large windows update on the
xp machine, (last week) don't know if it effected any drivers. Might I be missing necessary drivers? Cannot access
device manager when the usb storage hard drive is connected. Very frustrating
I have no hints as to what is wrong with old 'reliable' xp. Hope for help with this.