If you get this error message while trying to upgrade to Windows 10 1903, and you update your storage driver, but this message is still appearing, you have to go into C:\Windows\system32\drivers (WARNING, WHAT I AM ABOUT TO TELL YOU CAN HOSE AND DAMAGE YOUR SYSTEM. PLEASE MAKE SURE YOU HAVE A GOOD BACKUP THAT YOU’VE TESTED. I WOULD CREATE A RESTORE POINT JUST IN CASE YOU GET STUCK, I AM NOT RESPONSIBLE FOR ANY DAMAGES THAT MAY OCCUR TO YOUR COMPUTER BASED UPON THIS INFORMATION) and look for the iaStorA.sys file and rename it to iaStorA.sys_old. However, make sure you are seeing the updated Intel storage driver within Device Manager first.
Once you rename the file, you can go back out and re-run the update. This should get you past this error message.