You may be in for a long wait before Windows Update makes it available for your computer.
I’ll show you an easy way to install the update now without a lengthily wait before it is your turn (Microsoft will not make the update to everyone at the same time). So I'll show you how to get Windows Update to do its job now and download and install the update.
Two important things to do before you start the update when it becomes available:
A) Create an image backup of your current version of Windows 10. Should the update fail you can restore the image to your disk drive and try again.
B) Disable any third party Anti-Virus software you may have installed!
How to install the update:
1) Go to Windows Update, by opening the start menu, click on ‘Settings’ / Updates & security or in the ‘Search box’ type: update' and open ‘Check for Updates’. This will prep your system with any last minute minor updates before you install the Fall Creators Update.
Note: Laptop users should not install the upgrade while running on battery power only
Now click on the “Learn More” link.
2) Next it should open a page on your default browser. To continue with the upgrade click on the link as shown below.
3) Click on the "Update now" button.
4) Click on the "Save" button drop down and chose the “Save and run” option.
Note: This will download a small file located in the “Download” folder (windows10Upgrade9252.exe) which will force Windows Update to start the download of the Fall Creators update. If you choose to “Save” and not Save and run the file, you can run the file immediately or when you are ready by double clicking on the file to start the update process.
5) Once you see the windows as shown below displayed, to start the upgrade process click on the “Update Now” button located in the lower right corner.
6) If you see the message shown below you device is compatible and you can continue by clicking on the “Next” button located in the lower right corner.
8) The actual update process will start once the download completes. Please note that for whatever reason the update may take a while (appears to be stalled) to get past the 80% point.
9) You will need to “Restart” the computer to complete the update. You can force a restart by clicking on the “Restart now” button or wait for the countdown time to reach zero.
Note: You also have the option to use Windows 10 Creators Update ISO:
The Fall Creators Update will also available (on or after October 17th, 2017) using the Media Creation Tool.
https://www.microsoft.com/en-gb/software-download/windows10
Reference: https://www.pagestart.com/w10fcugetitnow0925171.html