You will need the Standalone Windows audio drivers
available from this page, and you will want to use the ASIO driver from that installation. I highly recommend you download and read the documentation as well, as there are certain limitations, especially the fact that Digidesign drivers are
single client drivers..
I'm curious though, why would you borrow an mBox for use with Cubase? There are lots of better choices of audio interfaces for Cubase. The benefit of the mBox is, IMHO, the ability to use Pro Tools.