O/S is RH Enterprise Linux ES 2.4.21-4.ELSMP
Using USB K/B on Optiplex GX280 system.
GRUB version .93
K/B works in O/S menu but fails after Linux loads.
Any help would be appreciated.
Thanks

Do you have all the needed modules compiled and loaded? You can compile them right into the kernel so you don't have to worry about them. If you are using disk encryption, you either need them in an intird or compiled in.

USB keyboard and USB mouse and the USB HID modules should not be compiled as built-in. Also they do not have to be in initrd file. There should be a file in RHEL to force autoloading usbkbd, usbmouse, and usbhid upon boot up. Using the 2.4.x kernel is also one of your problems unless you do not mind upgrading from devfsd/coldplug/hotplug to udev. Using udev is a better and more reliable choice for USB devices. If the computer has a PS/2 for the keyboard, use that instead for a reliable connection. Also adding noapic to the boot loader may have to use to get some USB device to work.