Why does my USB, Mouse serial not turn off??

[radium]

I have this problem with my new computer. Even with the computer shut down, the serial port for the mouse, and the USB 2.0 port that's connecting my network adapter don't shut off. I Think the motherboard is still constantly giving them power even with the system shut down. I can take care of this all with the power switch on the back, but I won't remember to do that every time.

The motherboard is a V17 PT800 series. Any help would be appreciated.