I have just installed a new motherboard, Matsonic MS8147C series, great bit of kit. I am using XP Pro and have found that I cannot shut down, as it immediately reboots. The board has the following information on the power switch;-The switch should maintain contact for at least 50ms to signal the power suopply to switch on or off. The time is due to internal debounce circuitry. After rerceiving a power on/off signal, at least two seconds elapses before the power supply recognises another on/off singal.
There is no other information that I can find on how to switch off.