If you’ve already reserved your free copy of Windows 10 from your Windows 7 Service Pack 1 or Windows 8.1 Update and the upgrade isn’t showing up, then you should try the following workaround. Microsoft is now gradually rolling out Windows 10 on 190 countries and on 111 languages, so as you may imagine trying to upgrade everyone will be a time consuming process.
However, if you want to skip the queue, you can manually trigger the download files to upgrade immediately. To do this, ensure Windows Update can download and install updates automatically. If you haven’t done it before, you can follow these Microsoft instructions.
Then navigate the following path:
Select and delete all the content inside the Download folder to start fresh with Windows Windows.
Now open the Command Prompt with administrative privileges – simply do a search for cmd on Windows, right-click and select Run as administrator –, then type the following command:
This should manually trigger the download of Windows 10.
Source Windows Central