It broke my file sharing.  Trying to access folders to the Window 10 system would have for a password. Even with "turn off password protection" enabled it would still ask for a password even after a reboot.  It also removed login without a password. The only fix was to roll back to Aug 21 via system restore.

You might fare better backing up, formatting (wiping) the partition and doing a clean Win10 install.
And check your network adapter drivers are up to date.

 I realized it was my Insider Preview and now stopped them.

Ah the f'update channel!

The latest 10 update even messed up Plat, some projects wouldn't even load! Did a restore back to 7. Windows 10 has way to many problems for me.

I am stuck at version  240 and cannot get the 1511 update, no matter what I try, it fails every method, HOWEVER, reading some horror stories plastered all over the internet, I am glad I cannot update

I had concerns about the update system for win 10 but decided to give it a go. Starting to regret it. It feels like every month I am dealing with a major problem. Several people have echoed "just rollback" but that is rarely that black and white and it always leads to lost productivity. So glad i left at least one computer on win 7.

One thing I've noticed with Windows 10 that's really annoying is that sometimes I will save an image file to my computer (e.g. an online photo) but when I navigate to the folder in Explorer, there is no thumbnail for the photo in question, just the generic image icon. Everything else in the folder has a thumbnail except the photo I just saved. If I wait a little while, or navigate in and out of the folder a few times, the thumbnail eventually appears. This has been the case from the first install of Windows 10 I did through every update so far. It says a lot when something as fundamental as image thumbnails is broken. 

I'm on Build 1511 and have had no problems!

Ham N Egz
I am stuck at version  240 and cannot get the 1511 update, no matter what I try, it fails every method, HOWEVER, reading some horror stories plastered all over the internet, I am glad I cannot update

I've had the same problem with one of my systems, not being able to update to 1511 for a long time. Microsoft Update has in the process caused that system to sometimes make continuous reboots, sometimes only showing a black screen and sometimes actually logging in but refusing to show the start menu, or doing anything at all.

Until now, the temporary fix has always been to roll back to the last restore point. But of course, that's not a long term work-around as Windows 10 soon will make another attempt to make that very same update. And again it will fail.

But today I found a fix on a Microsoft support page that actually worked, at least for me and at least this far. It involves running DISM.EXE and SFC as administrator in a command window before running Microsoft Update. I tried it and two hours later I was actually running 1511.
 
http://support.microsoft.com/en-us/kb/947821