Microsoft Security Bulletins September 13, 2016
For more info go here
http://www.ghacks.net/2016/09/13/microsoft-security-bulletins-september-2016/
I have not yet downloaded the Microsoft September updates on my windows 10 machine yet. Has this problem been corrected by Microsoft? As in the updates going more smoothly
Glad it worked for you. There's also this tip from the Ask Woody site for anyone else with the same problem.
https://www.askwoody.com/2016/if-win10-anniv-update-patch-kb-3189866-stalls-at-45-or-95-heres-how-to-get-it-going-without-using-ie/
Thanks, F 4 E.
I actually figured it out before seeing your reply. The manual install turned out to be more "manually" involved than I had expected.
But like you said, "It's a bit fiddly, but it works!" Thanks, again. 
Hi, Inquirer. Try the tips in this thread. http://www.tenforums.com/windows-updates-activation/50678-cumlative-update-windows-10-kb3156387-stuck-44-a.html
I had to go to Internet Options in IE, click the Security tab and temporarily disable Protected Mode.
After the download and install, I just re-enabled it.
On the MS page you just select the download you want, add to basket, click on that and then the Download tab.
It's a bit fiddly, but it works !
Hi, F 4 E.
I downloaded the Microsoft Update Catalog using IE and nothing happened. More specifically, I clicked "Allow" but there was no prompt telling me to do anything else after that.
Could you describe how you fixed the problem in more detail (including links)? Thanks.
Had great fun with Updates stalling at 45%. By Googling, I found I wasn't alone.
Fixed issue by logging onto Microsoft Update Catalog using IE, and installing manually.
Particularly KB3189866 which takes you to 1607 Build 14393.187, if you have the Anniversary Update.
Well done, MS !