This USB port and external drive have been fine together until today when I plugged in the USB external Passport drive, it caused the system to shutdown /reboot and show the abnormal shutdown screen. Tried 3 times, same process. No problem using this drive on another computer.
Some research pointed to possible grounding or static issues, but don't understand how this type of problem happens when no changes have been made, nothing moved, and the environment is the same. There are two USB ports in front, one for the USB wireless mouse and it functions fine, the other is the one which is causing the shutdown. I'm pretty sure the Power Supply is large enough to accommodate all the USB elements.
This is Windows 7 Ultimate.
Any ideas? What to check?