Windows XP Blue Screen shutdown - USB device not recognized

The last time I had my 1 TB MY Book connected a couple of weeks ago, it worked fine.

I usually keep the USB connected, but disconnect the power when it’s not being used.

Today, while the power to it was still disconnected, I received the prompt from Windows XP:

USB Device not recognized. One of the USB devices attached to this computer has malfunctioned. The location of the device is shown in bold type, USB Root Hub ( 2 ports) – Unknown device & Unused port. The unknown device is the one in BOLD. Recommendation – Try reconnecting the device. If Windows still does not recognize it. Replace the device.

I wasn’t sure which device it was referring to, so I connected power to the My Book, and after a few blinks on the My Book, I got the Windows Blue Crash screen which shut down the computer, indicating a bad_pool_header.

Please advise.