You can check what you have downloaded by using this method:
ISO - See what Language, Edition, and Architecture of Windows 10 - Windows 10 Tutorials
Instead of mounting the ISO file, you can just use the drive letter assigned to the Windows 10 USB flash drive or DVD you created when it is inserted. Under version: you should see 14393.0 if you have the Anniversary Update created.
10240 is the original Windows 10
10586 is the November, 2015 update
14393 is the Anniversary update
What I like to do if there is problems with updates on install is to do the clean install with no connection to the internet - unplug Ethernet cable and do not sign onto any WiFi. When asked to create a user account, look for the little links that allow you to skip all the Microsoft Account and email account steps and create a local user account. Log in and let everything settle down. Then connect to the internet and let Windows 10 just do the updates in the background, waiting for the notification that a restart is required. When I get that notification, I go to settings, Updates & Securities, and the updates tab. There should be a reboot or restart now button under available updates. I use that to restart the computer.
If you want a Microsoft account login, you can just convert the local account to use a Microsoft Account. Another advantage to doing the local account first is that I get to pick what the folder under C:\Users will be because it will be the same as the username I enter for the local account and does not change when you convert to a Microsoft Account login.
Many thanks NavyLCDr - you are a lifesaver - that update kicked in - a moment before it was due to go out the window !
to anyone else - just note that KB3201845 is a hefty update 75omb - so wait it out - mine stuck at 20% for ages !!