I'm running Mandrake 9.2
During the install process the USB keyboard worked fine, I was able to handle all dialog boxes and type in user names and passwords.
When booting Linux, the boot process hangs at the 'Looking for new hardware' stage.
The only reference to USB in the bios is 'support legacy devices', no mention of USB keyboard support.
I also tried forcing loading of the hid.o module but it doesn't help.
Other USB devices (camera, scanner, printer) all work fine.

Finally, I dual boot to windows 98 and there the keyboard works OK, so we can rule out BIOS or hardware problems.

Any ideas gratefully received.

can you boot when the keyboard is unplugged?

if you can, reconnect the keyboard when the boot is completed and see if it works. If it does, go to mandrake control center and then to drakxservices and disable harddrake from starting up at boottime and see if you can now boot with the keyboard attached.

I followed your advice and was able to complete the boot sequence when no keyboard was plugged in.
After KDE came up I plugged in the keyboard but couldn't type anything. It also froze the USB mouse!.

I moved the mouse to PS/2 and repeated the experiment.
I then went into BIOS and tried the enable/disable/auto settings for 'USB support legacy devices'.
I also tried disabling harddrake at boot time.

None of the above worked.

Next I replaced the PS/2 keyboard and booted up. When plugging in the USB keyboard, syslog displayed the following:

May 25 14:58:04 localhost kernel: hub.c: new USB device 00:04.2-2, assigned addr
ess 2
May 25 14:58:04 localhost kernel: input0: CHESEN USB Keyboard on usb1:2.0
May 25 14:58:09 localhost /etc/hotplug/usb.agent: Setup usbkbd hid for USB produ
ct a81/101/110
May 25 14:58:09 localhost /etc/hotplug/usb.agent: Setup hid for USB product a81/
101/110
May 25 14:58:10 localhost kernel: usb.c: registered new driver hiddev
May 25 14:58:10 localhost kernel: usb.c: registered new driver hid
May 25 14:58:10 localhost kernel: usb-uhci.c: interrupt, status 2, frame# 396
May 25 14:58:15 localhost kernel: usb_control/bulk_msg: timeout
May 25 14:58:25 localhost last message repeated 2 times
May 25 14:58:25 localhost kernel: input: USB HID v1.10 Device [CHESEN USB Keyboa
rd] on usb1:2.1
May 25 14:58:25 localhost kernel: hid-core.c: v1.8.1 Andreas Gal, Vojtech Pavlik