b0!? Have him get that WIndows drive out of there as a precaution.
If OS X is on the same drive as Windows...then it sounds like for this mobo, he may be better off getting another drive.
EDIT: OK, it is the same drive. Sorry I forgot that bit. /facepalm

Some other general ideas...
1. Try reinstalling with SATA set to IDE mode, as it may help. Assuming, of course, you already tried AHCI.
2. Installing all the network drives may only serve to complicate things. Uncheck everything but those whose brand matches what you have (ie RTLs for Realtek, etc. depending on what LAN chipset is on the mobo)
3. Leave out the video card and leave all the videos drivers unchecked. This may also be putting a cork in things.
4. If all else fails, get an IDE drive and try with that. You can probably get a 20 or 40 gig used on the cheap, and that will be enough for OS X.