try
http://www.redhat.com/docs/manuals/e...iguration.html
since you state you can not find any other monitor I assume you also mean generic so you may need to run if X config tool does not work....a manual tool
most distros have such...try with root powers
xorgconfig (mine is in /usr/bin) and follow the prompts but before you do...make sure you have backup of your current file and know how to use a live cd to re-store its name if your new file causes a crash.
It is generally better to edit /etc/inittab to a runlevel (i am guessing redhat's) to a non-x one of 3?....your file may tell you.
the reboot....login and change to root and then run
/usr/bin/xorgconfig
if no errors....next command gets gui
startx
then edit inittab back to old setting maybe runlevel 5