If you're trying to use the Media Creation Tool to upgrade to the latest release of Windows 10, sometimes it might get stuck trying to download updates before the installation begins. How can you fix this problem?
The quickest workaround for this problem is to restart the Media Creation Tool, and then proceed with the on-screen instructions as directed. However, after the application finishes downloading the files, quickly disconnect your device from the network by unplugging the network cable or turning off the Wi-Fi adapter.
Disconnecting from the network will cause your device to timeout trying to download the updates, which will cause the Media Creation Tool to skip the step and continue with the installation.
Once the device has been upgraded to the Windows 10 Fall Creators Update, and you're in the out-of-box experience (OOBE) finishing the setup, reconnect your device to the network. Then the final thing left to do is to go Settings > Update & Security > Windows Update, and click the Check for Updates button to install any missing updates.