I kept getting the something happened before the update would even load up to the first page.
Found this solution on reddit now have windows 10 on all my systems issue free
I was seeing the Something happened 0x80070002 - 0x20016" error (as per image below) when running the media creation tool as well. What worked for me was the following fix from Reddit. I was having to run the tool as I hadn't recieved a notification to reserve a copy and it wasn't showing up in Windows Update until the below change in the registry.
Click on Start, search for regedit.
With regedit open, proceed to the following path. Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\WindowsUpdate\OSUpgrade
Right click on the right side window and go to New -> DWORD (32-bit) value
Rename the new value to "AllowOSUpgrade" without the " quotations and make sure it is exactly the same as it is case sensitive.
Double click on the newly created value AllowOSUpgrade and change the value to 1 with hexidecimal base.
Close regedit and run Windows Update again. Windows 10 should pop up and you can then download it.