Somewhat spotty but do ask HP if the motherboard drivers are their best or latest. Same about the BIOS.
"does anyone know why it would do this?"
Yes, but you need solutions, not a "why?" answer.
My computer, HP running vista 64-bit, won't shut down when I have my my 1TB Western Digital My Book Home Edition attached. It is attached with and eSATA cable. The computer starts to shut down, but when it gets to the screen that says "shutting down" it just stays there until I unplug the external hard drive. does anyone know why it would do this? Thanks