More than likely, your xfree86 setup isn't correct. To fix it, hit <ctrl><alt><F1> once your system starts to do that. This will put you in text mode. From there, log in as root, with your root password.
The steps you take next depend on your distribution, and I haven't used redhat for a while. If they have an easy text-based setup, that might be your best route. For a more basic route, type:
xf86cfg -textmode
This will put you into xfree86's setup. It's pretty easy to use, too. From there, you may just have to play around to find a setup that works for you. (If you can't find your actual setup, try a configuration that is less than what you are using, and go back and fix it once you know more about linux) After you're done, save and exit. Then, type startx to start the windowing system again. Repeat as necessary until you get it working.
One thing to note, if you type startx, and you get a response that the server is already running, you'll want to do the following:
ps -A|less
this allows you to see running programs. scroll up and down with the arrow keys, and look for a process called xdm, gdm, or kdm (these are programs that start your graphical system). Remember the number all the way to the left. This is the process ID (PID). Then hit 'q' to quit. At the prompt, type:
kill -15 <PID>
without the brackets. This stops the running program. Run 'ps -A|less' again, and make sure xdm/gdm/kdm is now gone. Then, type:
gdm
or xdm, or kdm, depending on which one you stopped earlier.
I know this sounds complicated, but it works, no matter the problem, and gaining familiarity with 'ps', 'less', 'kill', can help you out in the long run. If you're more curious about these programs, man <nameofprogram> can tell you more. Anyway, it's a lot easier than it sounds.
