Hi I have the same issue with WinPE for some older DELL Optiplex models - as soon as SCCM media boots up into WinPE and we have to type in the password before starting the Task Sequence, the keyboard light goes out and then we can do nothing. I have tried adding USB drives to the boot image, that didn't help unless they weren't the right USB keyboard drivers. We need to be able to bootup using standalone media for those standalone workstations which are not able to get onto network. After tearing my hair out for a few days, I did find a newer USB MAC keyboard worked! I am using this keyboard for the time being but a bit of a nuisance so we need to find a long term solution.
