Then you are like me, and Windows 10 free upgrade is not working. Here is the solution I used.
Go to C:\Windows\SoftwareDistribution\Download and delete everything inside that folder (I have already deleted it and started the Windows 10 upgrade process):
After you delete what is in the C:\Windows\SoftwareDistribution\Download folder, open up a command prompt as an administrator and type: wuauclt.exe /updatenow and hit enter.
After this, open up your windows update and you should see the download has already started.