ATI and NVidia graphics cards are known to be a problem with FC5....
Boot into runlevel and at least get a generic X11 configuration going.
When the grub splash screen is displayed press any key
Select your Fedora Core 5 boot choice and press the 'e' key
Select the line the begins with 'kernel' and press the 'e' key
At the end of the line add a space followed by the number 3
When done press the 'Enter' key followed by the 'b' key
Log on as root and do;
cp /etc/X11/xorg.conf /etc/X11/xorg.conf_mybackup
system-config-display --set resolution 800x600 --set depth 24
You can then test by using; startx
If this looks OK then your done if not then try the system-config-display command again and set the depth to 16
Also read;
http://www.linuxquestions.org/questi...d.php?t=420876