For those getting a Windows 10 install error 80240020 when trying to install Windows 10, try the following:
- Browse to “C:\Windows\SoftwareDistribution\Download”
- Delete everything in this folder. – This will delete any corrupt files.
- Run command prompt as an administrator and type the command “wuauclt.exe /detect now” followed by enter.
- Go to your control panel and then Windows update – check for updates and it should start re-re downloading Windows 10.
Failing that, see this Microsoft article: