Can’t Install the Anniversary Update

This would have to be one of the most prevalent complaints on help forums at the moment… Windows 10 Anniversary Update installation failures. While the Anniversary Update appears to be installing successfully on the vast majority of machines, there is obviously a quite significant number where this is not the case – including my very own. In my case, the installation has been consistently failing at around 75% following the second restart and with the following error message:


What’s most frustrating about my situation is that I have 4 machines running Windows 10, three older machines and one quite new machine with modern specs, and while all three older machines with outdated and unsupported drivers have installed the update just fine, the newer machine flatly refuses to cooperate. I’ve tried installing the Anniversary Update via Windows Updates, via the downloaded Windows 10 Upgrade executable, and even via a mounted Windows 10 1607 ISO, all to no avail.

What’s most frustrating for users facing this predicament is that nobody appears to have a clue why the update is failing. When an attempted installation fails an error logfile is created in a $Windows.~BT folder in the root of the C (system) drivethe full path to the logfile is C\$Windows.~BT\Sources\Panther\setuperr.log. Trouble is, much of this error logfile is indecipherable, at least to anyone less than a computer scientist with advanced knowledge of Microsoft’s error reporting system. Here’s an example of the setuperr logfile which was created following my last failed attempt:

Click image for full size

Click image for full size

Obviously, the full width of the logfile contents wouldn’t fit on this page so I had to reduce it accordingly, but you get the idea. Even Microsoft MVPs are ignoring the contents of the logfile when posted by users seeking assistance, preferring to respond instead with a generic list of “things to try”. These lists generally include:

  • Completely uninstall antivirus software. When I asked a Microsoft MVP what the difference was from simply disabling the antivirus and all its associated services, he responded with: “Disabling will turn off all its functionality while uninstalling it will remove all its components“.
  • Remove all USB devices other than mouse and keyboard. This one makes sense. It’s a known fact the Windows installations will baulk, for example, if a USB external drive is connected. I’ve even read where users reported successfully installing the Anniversary Update after removing the wireless mouse’s USB receiver, although I find that difficult to comprehend.
  • Install in clean boot mode. Again, this makes perfect sense. Clean boot mode disables all startups, including security software, as well as all non-Microsoft services, thereby mitigating the risk of security software interference as well as potential third party software incompatibilities.
  • Disconnect from the internet. No idea why this might make a difference – perhaps to prevent software from phoning home and potentially disrupting the installation process. Regardless, it is a common suggestion, albeit always devoid of further clarification.
  • Update the BIOS. Again, I can’t really see why this would make any difference but hey, worth a try, right?

I’ve tried all of the above plus many other suggestions and potential solutions as well (including updating drivers), none of which have made a blind bit of difference. To add to the confusion, all of my other (older) machines installed the Anniversary Update perfectly with no such precautions or measures necessary.

Anniversary Update Fails – 2 Important Steps

  1. Before – Create a full system image backup: Make sure to create an image backup prior to installing the Anniversary Update. With an image backup safely tucked way, if a failed installation creates any issues, you’ll have an effective fallback position in place.
  2. After – Run sfc /scannow: One thing I did discover is that when the installation fails and Windows recovers to the previous version it invariably leads to system file corruptions. Sometimes running the sfc /scannow command will repair the corruptions but not always. So, if you’ve gone through this failed install>recovery process, you should always run sfc /scannow to check the integrity of your system.

To run sfc scannow you’ll need to open an elevated command prompt. Right click the Start button and choose Command Prompt (Admin), then type in sfc /scannow and hit Enter:


To give you some idea of what I’ve been going through this past week or so, here is a list of steps I’ve had to go through, including approximate times to completion:

  • Download the Anniversary Update: Approx 45 minutes
  • Go through the installation process: Approx 1 hour
  • Automatic recovery to previous version: Approx 10 minutes
  • Run sfc /scannow: Approx 20 minutes
  • Restore image backup (in case of corruptions): Approx 30 minutes
  • Start all over again trying something new

All up we’re looking at approximately 2hrs 45 mins per attempt (except for those attempts via the ISO which eliminate the time to download). Multiply that by the 14 attempts to date (call me Percy Verance) and you’ll understand why I haven’t written any articles this past week or so. I’ve been reluctant to clean install because I have $600+ worth of programs I’ve paid for which may or may not re-activate. Besides, I hate letting anything get the better of me. However, I do recognize when to admit defeat and so will be clean installing in the next few days. I’ll let you know how I get on.

Cheers… Jim

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About the Author

Jim Hillier

Jim is the resident freeware aficionado at DCT. A computer veteran with 30+ years experience who first started writing about computers and tech back in the days when freeware was actually free. His first computer was a TRS-80 in the 1980s, he progressed through the Commodore series of computers before moving to PCs in the 1990s. Now retired (aka an old geezer), Jim retains his passion for all things tech and still enjoys building and repairing computers for a select clientele... as well as writing for DCT, of course.