Fix - Windows 10 failed to install error Code 80240020
restart the system before deleting the files
Step 1 : Navigate to "C:\Windows\SoftwareDistribution\Download"
Step 2 : Press ctrl +a and delete everything in the folder.
Step 3 : Open the command prompt as an administrator.
Step 4 : enter the following command
Step 5 : Open the Control Panel > Windows Update
Step 6 : Windows 10 should start downloading from begining
update to windows 10 pro failed,
windows 10 couldn't be installed,
windows 10 update fails to install,
windows update upgrade to windows 10 failed
unable to upgrade to windows 10