Reconfiguring X on RH 6.2

Hi,

I have installed X-windows on Red-Hat 6.2 and configured X-windows at the install time on a 14″ inch monitor. Now that I had repalced it with a 21″ inch monitor, I tried
Xconfigurator, but the command didn’t work. Is there any way to turn this around or do I have to reinstall the LINUX system.

Regards

Amal