Which version of Windows 10 is currently installed? See how to verify:
https://answers.microsoft.com/en-us/windows/wik...
Make sure you are running the latest version, Windows 10 1903 then try again:
Download the Media Creation Tool Now
http://go.microsoft.com/fwlink/?LinkId=691209
Right click the MediaCreationTool.exe file then click Run as administrator.
Accept the End User License Agreement:
Select the option Upgrade this PC now if you want to upgrade right away,
Click Next
Accept the End User License Agreement.
Wait while Windows 10 setup does one final check to ensure your system is ready.
Windows 10 setup will check if you have enough disk space. If you don’t, review the following article for instructions how to upgrade to Windows 10 Anniversary Update on a system with limited space:
Please note, you have the option of choosing what you would like to keep, which includes personal files, apps and settings.
If you want to perform a new install or just keep your files click Change what to keep. Once you have chosen the desired options, click Install to begin.
This will be your screen for a little while. During the installation, your computer will restart several times.
After the first restart, Windows 10 setup will resume. You will notice the setup experience has once again been refined from the previous animated circle. This will be your screen for a while. When complete, Windows 10 setup will restart automatically.
Sign into your account.
Wait while Windows 10 completes application updates and post setup tasks.
That’s it, the Windows 10 Feature Update is installed.You can check Windows Update for latest updates, click Start > Settings > Update & security > Windows Update > Check for Updates.
How to prepare your computer before upgrading?
Although updating to Windows 10 version 1903 is a relatively simple process, similar to a repair upgrade; users should perform some basic pre-requisites before initiating the upgrade.
If you are finding it difficult to carry out some of the steps described below, please review detailed instructions how to perform them:
https://www.groovypost.com/howto/prepare-comput...
Information in the above link is sourced from a trusted Microsoft MVP blog.