This post is valid for the Upgrade initiated by the Windows10Upgrade28084.exe , with which I have had success so far already on 2 other Laptops.
Please, tell me how to get some info of the reason on Windows 10 Anniversary Upgrade stuck at ab. 32% done, just after the second restart at 30%, during the actual final update process phase?
This Laptop is freezing with no picture on display and power-on, and, not reacting to any mouse/keyboard signals, forever, until an emergency shutdown, pressing power-off for 6sec.
There is no hints for the problem on Windows System/Application logs.
I have been checking and applying for this several hints from net, but still always the same result on some 3 consecutive Upgrade trials …
Note, that anyway one prerequisite has shown to be essential for this Upgrade, namely KB3176493, which is a part of Windows 10 Update to 1511 10586.545 level.
Best Answer
Had the same problem with a laptop. Update failed twice at about 32%. The laptop automatically rebooted to the unupdated Win 10. Tried a trivial approach. Went wired instead of wireless. Update failed at about 40%. On the fourth attempt - turned off other computers on the router. The update completed successfully. Do not know whether this approach or just being persistent was the key to ultimate success.