Let's start with the basics...
Are you sure your CD drive is functional? Do other disks run normally in it?
Do you have a DVD disk and you are trying to install from a CD-ROM drive? If
so, you need to install a DVD drive or get the CD version of Office
(actually, I'm not sure if the H&S version comes on a CD or DVD...I don't
use that version, but it's worth checking out)
If Setup doesn't start, it's not related to having to uninstall another
version of Office.
If the above are OK, open a Windows Explorer window, go to the Office disk
and double-click on the "Setup" file...that should start the install
process.
Please post back with an update if the above doesn't answer the question.
Tim