Laptop keyboard unresponsive

I have two Dell laptops and both of them have unresponsive internal keyboards at startup.  If I plug in an external keyboard, delete the internal keyboard, and restart them they reload the driver and the internal keyboard works fine for that session.  One of them started this behavior a couple weeks ago and the other one (a brand new laptop less than a month old) started yesterday.

Any suggestions on a likely cause and/or fix?  Thanks for your help!!