1.grab a old floppy and a usb pci card
2.on a friend computer put your sata hard disk install the OS
3.switch back to your computer with the floppy and the" pci usb" plug your keyboard only in it
4. you're good to go (Os boot but still no access to bios)
Ps: the usb are working but no data are transmit(maybe not enough power) ;
my method worked with linux did not try with windows;
if it dont work try to use a usb hub with external power !!
My xps400 has stopped recognizing usb keyboard and mouse. I've tried installing as ps/2 IO card, but it had no effect.
Short of replacing the motherboard, how can I fix this?
I had this problem and solved it...
Deatils of my case: My computer is a Dell 5150 although I have read about this same problem on Dell 4xxx, Dell 8xxx, Dell 9150 and Acers as well. When booting, I would get a message "keyboard failure, press F1 or F2..." I have a known good USB keyboard, there are no PS/2 ports. I tried added PCIe USB card and reseting the bios, neither worked.
After noticing and replacing four buldging capacitors (6.3v 820uf) on the motherboard, my keyboard worked.