optical mouse won’t shut off

I have just got a BTC optical mouse
and it won’t shut off when i shut down my PC. The lights on the mouse are still on
I have installed all the drivers correctly and seems to work fine all the buttons and
scroll wheel. It is connected to ps2 port
on a Gigabyte GA-6VXE7+ ver F4 if that helps

I have tried and Microsoft optical explorer on this PC and the lights also don’t shut off

Much help would be appreciated

Thanks in advance
J Chew