Usb or ps2 keyboard? Some motherboard bios have the usb keyboard setting disabled by default. You shouldn't need a driver, unless your usb driver didn't load properly. Check windows device manager in the control panel for marks next to any of the usb device drivers. You may need to update windows with a service pack or simply select windows update and let microsoft search for a device driver.
It's a ps2 keyboard, going into a usb. I can't get past the boot screen - keyboard not found, press f1, f2.....