I had the same problem with customers of mine.
For those who don't require password entry. After booting up. Don't touch the keyboard keys. Use your mouse and right click on my computer. Select properties > Click Device Manager > On the Keyboards, Uninstall > Close everything. Locate Control Panel > run Add Hardware. This well detect the keyboard and you should be running.
I haven't found a way for those who are required to type password and work around. Good Luck