Pavilion N5475/Trident Cyberblade XP

I'm just trying to get started on Linux on my XP system. I've already installed Red Hat 7.2, but X is driving me crazy. Whenever I boot into graphical mode, it shows a standard command prompt log-in, and the screen will flash every second or two and not allow me to type anything, before eventually warning that the process is respawning to frequently and acting normal for a while. I'm running on a HP Pavilion N5475 laptop with a Trident CyberBlade XP on it. I've tried several different video configurations to no success, and have not been able to find any workaround for it. Not that I mind using the command prompt . . . but it would be nice to find out what Gnome and KDE are like. Someone please help!