Hello! Today I wanted to upgrade my Windows 10 Home TRIAL version to Windows 10 Pro TRIAL version (so no money spent) without full reinstallation (usb). I just couldn't do it. I found that you can try going on Windows store, updating it and then you are able to find Windows 10 Pro on it, but, for me, the update didnt show up. Also i tried going to settings > activation > go to store, then i needed to purchase the Windows Pro. So... thats it. My question - how?