That's the downside of belarc advisor -- it can only list devices for which drivers are installed. It's only of any real`use in identifying the motherboard make/model. Just about everything else it tells you can be obtained from Device Manager.
The hewlett-packard website provides all the drivers for the zt1175, but, apart from the modem, they are all consolidated into a single download of 45MB:
http://h10025.www1.hp.com/ewfrf/wc/s...13 07&lang=en