- Power down the computer.
- Wait 5 mins
- Start machine again and Windows 10 setup will restore the system to the previous version of Windows.
- Try installing the update again, do the following before:
1. Open a Command Prompt (Run as Administrator)
2. Type: cd %windir% and press the Enter key.
3. Type: net stop wuauserv and press the Enter key
4. Type: ren softwaredistribution softwaredistribution.old and press the Enter key.
5. [ Note: if you get an error message, ignore and type the above again and press Enter ]
6. Type: net start wuauserv and press the Enter key.
7. Type: Exit and press Enter, then go back and check for Windows Updates again.
When the download reaches 100%, disconnect from the Internet immediately if you are connected by Ethernet or Wireless.
Proceed with the installation and hopefully it will update.
This work around discovered by Community Member Hula_Baloo has been a success for many.
If you have attempted this method, I suggest you skip upgrading and setup a dual boot configuration instead:
How to dual boot the latest Windows build with previous versions of Windows