I couldn't figure out the problem so formatteed the drive and did a clean install of XP. This time, instead of doing the XP auto updates, I first loaded the video drivers from CD (gagp30kx.sys mentioned before is an AGP driver so wanted to make sure it wasn't the culprit). System reboots fine. After a couple of restarts, my internet connection stops working device manager shows no conflicts here and comp keeps trying to get IP address but fails; laptop on same router was fine. I unistalled ethernet drivers, restarted and updated them from ASUS mobo CD along with the audio drivers. Upon restart, I get the same blank screen problem again (can't do safe mode or repair windows). In the interest of full disclosure, my device manager had yellow questions next to 2 devices: audio and unkown pci device. that is the reason why i installed the audio drivers from mobo CD. Re: the unkown pci device, no idea what it is (I have no PCI cards plugged in). System = CPU + mobo + 2 RAM DIMMs (work fine in other comp), 2 HDDs, 1 video card (worked fine in other comp).
Finally, before this try, I had done a clean install of XP, then installed drivers (audio, usb, via chipset, ethernet) from the mobo cd and restarted. Got the same blank screen problem as well.
Interestingly, I have installed XP onto my old ATA100 hard drive and that seems fine for now (only performed auto updates and mobo driver updates mentioned above). However, after working fine for hours, now the internet connection doesn't work (no hardware conflicts, just keeps trying to get IP adderss). I have already restarted the router to reset settings but to no avail.
I am completely stumped here - any help will be greatly appreciated. Thanks.