Hi there, I, by mistake, plugged the keyboard into the mouse ps2 port and the mouse into the keyboard's port. When I realized none of the two responded after windows started, I switched the PC off (a new e machines) and plugged them back to their respective ports. When starting again the keyboard worked perfectly, but the mouse did not. I know I can still use a usb mouse, but I need to know whether it was the mouse or the motherboard's ps2 that went bad and why. I, at the moment, don't have another ps2 mouse to try to rule-out it was that mouse that stopped working. Thanks in advance, osmany.