Have a dell computer when it starts up the moniter

have you tried using a ps2 keyboard to see if that is working. If this works and the lights powerup on the keyboard when you power the machine on then there is connection to the keyboard. If not then possibly you have a Motherboard failure.

Hello there:
I would first try this .
use a different monitor and keyboard (one at a time) and reboot each time and see what happnes just to check things out.
If it still happens than you know it is related to the computer and not the monitor or the keyboard
If not i would unplug the power cord from the computer
open the case and check to see if there is any thing that has came loose.
check all of the cables and cords and the memory sticks.
also remove the power cord that goes to the motherboard for 2 minutes and during this process press in the computer power button for 20 seconds now plug in the cord bac k into the motherboard and plug in the power cord for the computer and reboot
if it works great but if the monitor just works
you can use the mouse go to device manager and uninstall the keyboard by right clicking on the device and selecting remove than confirm the removal of the device and click yes and reboot the machine upon restart the computer will bring up the found new hardware wizzard and it will reinstall the device for you ok now you should be able to use it again but if nothing is working sorry to say you might be looking at a motherboard issue ok
I hope that this has been very helpfull for you
best regards michael