When trying to do the update I am told that my version is 10586 and that I need to be at 14393. I tell it to go ahead and do the update and it gets to 2% and then it tells me something went wrong and gives me error code 0x80070005.
I know this is odd, but I saw this on another site and it has worked for me on 2 computers so far. Click on the anniversary update, let it check your system and then let it download the update. As soon as it starts to update, disconnect the wireless or LAN. It was able to update after this. Once it got past this section, I connected to the wireless again. About to do this with my 3rd computer. None were able to update before.