I tried to start up my computer and i get an error message saying that windows cannot verify the digital signal for this file. It tells me to reboot and use the windows cd to repair it, but the thing is my keyboard only works half the time. It works when i first start up the computer so i can get into the bios but it wont work when i have to press any button to boot windows and it wont work when i get the error message. i tried using a different keyboard and it did the same thing.