Wait, wait, if your speakers are not connected to the mbox then you will NOT get playback through them when the mbox driver is selected. standard. The speakers should come out of the mbox, thats what you buy it for, to be the soundcard in your system!
The green output on the computers soundcard will not work when the mbox driver is selected without some serious fiddling around. You need to plug you speakers into the mbox and use that for playback. It doesn't need to mean buying studio monitors. I assume your speakers are stereo mini jack in? If so you just need to buy enough adapters to get from dual mono jack outs on the mbox to stereo minijack socket. I did this with my first setup way back when. Something like 'dual mono jack to stereo socket converter', then probably 'stereo big jack to stereo small jack converter' to get to your speakers.
If you are plugging your speakers into the computer soundcard and expecting pro tools to run that along with the Mbox then its just not gonna happen without a lot of fiddling and I'm surprised it hasn't been mentioned on the thread already. To put it simply the mbox takes over the job of your computer soundcard entirely when in use, this is not a problem, its just how it works! No need for installing and no real evidence of other drivers nabbing priority. Plug it in like this and see if it works, if not then we can start suggesting alternative solutions.
