Keyboard not workin at boot and stuck at starup repair

Hello,

usb keyboard not working in boot in windows 7.I tried ps/2 keyboards , connectng in different usb ports,cleared cmos.the main problem is while booting a optio named startup repair is showing.since i cant use my keyboard ,i cant select ' windows start normally' .then the pc autimatically select startup repair and i am stuck. in the next screen i cant do anything.