I thought it would be a good idea to inform those who have a Toshiba laptop about a problem I just encountered. My wife has a Satellite C675 that has been upgraded to Windows 10 for quite some time. Last Friday she complained about some of the keys on the keyboard not working. I had replaced the keyboard several months ago and thought that it must have gone bad. However, when I looked into it further I found the keys that did not work would work if I held down the Function Key while pressing down the non-working key. This made me think it might not be the keyboard as it seemed more like a key mapping problem than a hardware problem.
After looking at the Windows updates that were done around the time the problem appeared, I noticed that the keyboard had been updated to a Lenovo brand keyboard. After deleting the keyboard driver and restarting the computer the problem disappeared. The rub is that after doing another Windows update the Lenovo driver was reinstalled and the problem was back.
There is a way to prevent certain updates from installing in Windows 10 and the method can be found here:
In the web page referenced above a file named "wushowhide.diagcab" can be downloaded. Double clicking it will cause it to open. It allows individual updates to be marked as not being available for installation. I found the Lenovo keyboard update and toggled it off. This keeps it from installing during further update sessions. I have used this utility on my Asus laptop to keep Windows from installing a touchpad driver I did not want installed. It works very well. Sometimes I have to run the utility again as Windows might override it a few months down the road but it doesn't happen often. Here is a web site that shows how to use this utility: https://www.tenforums.com/tutorials/8280-hide-show-windows-updates-windows-10-a.html