How do I get my CD drive to read multiple volumes?

I have a two-year old CD that was created on a Mac at two
different times. Hence, the CD contains two separate
sessions or volumes which display as two separate icons
on a Mac desktop. On my Mac, I can access either volume
by simply clicking the icon. On my PC I am unable to
even see the second volume, from which I urgently need to
extract data. How may I direct my PC to read the second
volume so that I may retrieve the images I so badly need?

Thanks for any help!