errors installing SOF and Quake III

ok, I attempt to install SOF on an A7A, asus V7100, 256 DDR, IBM 40g 5400. At random points durring the install ( attempted to install several times, same error just at different percentages) I get a "_ins5576 has caused an error in ZDATAI51.dll
_ins5576 will now close". One time I got it to install all the way and got a "error durring intialization" and the game wont run. On Quake III, it will install all the way but give me a "vm/ui.qvm has bad header" error everytime I attempt to start the game. I have uninstalled and re-installed several times there also. I have tried replacing :
Video Card (w/ ATI 32m Radeon, 256 DDR, 1.2 athlon c, cd-rom, ide cable)
Still get the same errors.
Also, I had the problem first on Windows 2000 and now the same problem after I deleted 2000 and now have ME on there.
I can't figure out whats wrong. I am down to it possibly being the motherboard or hard drive. This is a new build. (first time i tried to copy cabs over from cd-rom and ran setup I got a corrupt cab error.)

PLEASE HELP!!!!

Thank you,

John