Firstly I know very little so feel free to treat me as stupid!

The onboad keypad/keyboard is very unreliable with keys not working or putting up double letters or letters totaly unrelated to what you want. I thought I could get round it by plugging a PS2 keyboard into the PS2 socket in place of the external mouse (changing that to a serial) problem is sometimes it works but more often than not it doesn't. I have tried several k/brds even a couple of old win 95 ones that I have to nill effect.

Am running win 95 because it does what I want and runs faster and takes up less space. Have formatted hard drive and reloaded to no effect.

Can anyone tell me why an external k/board does not work. [ps2 mouse works [when connected] no problem in same port?

Did you get any help to your problem, I had som problems with my 420cdt and I upgraded my Bios but i think the built-in keyboard started to act viered like yours after that. But for me using an external keyboard works but is rater frustrating.