Maybe somebody will come along with specifics, but my guess is to use a USB port on the back I/O Panel, but I don't know which one. If you don't have the Software Guide, maybe something about it is in there;
[url=http://msi.com/product/mb/Z77A-G45.html...
[url=http://msi.com/product/mb/Z77A-G45.html...