Yesterday (28th of July) Microsoft started upgrading Windows 10 on client machines. But as you know not all of us will be able to install the new version just right after this date. On my one PC, where I had Windows 10 Technical Preview I got final version 1 week before official release. But on my laptop also with Windows 7 I currently I didn’t get this update yet.
I found one solution:
- Enable automatically Windows Updates
- Delete the content (files and directories) in the C:\Windows\SoftwareDistribution\Download folder
- Open cmd as an administrator and execute command: wuauclt.exe /updatenow
- Up should be able to download and install Windows 10 (in Windows update option)
This solution supposedly work but only in Windows 8/8.1. And what if I want to upgrade my Windows 7 right now. We can use Microsoft media creation tool – you can download it right here. After downloading just run this program and wait until download is complete 
And here you go, you are ready to install Windows 10 – on demand.
Here is one strage change. I’m using polish Windows distribution but I changed language to english. As you can see right now, installer change language to polish 
So here is “preparing (29%)” and the second screenshot – “almost ready”.
P.S.
you can use this tool to prepare offline installation for another PC