Microsoft provides some more information about how it will handle the launch of Windows 10. If you're running Windows 7 or Windows 8.1 you can reserve your copy via the Windows icon in the bottom right corner of your screen but this does not necessarily mean that you will be getting Windows 10 on the July 29 launch date.
In a new blog post, Microsoft explains the final version of Windows 10 will first be rolled out to Windows Insiders, the around 5 million people that are currently running the Windows 10 Preview versions. They will be getting Windows 10 starting July 29.
If you are not a Windows Insider it may take a couple of days (or longer) before you get your upgrade to Windows 10. Microsoft is going to take things slow and plans to roll out Windows 10 in daily waves, slowly scaling up after July 29th. The software giant hopes this approach will reduce problems as it will have the opportunity to listen, learn and update Windows 10 after each roll-out.
How To Know When You’re Ready to Upgrade
Starting on July 29, we will start rolling out Windows 10 to our Windows Insiders. From there, we will start notifying reserved systems in waves, slowly scaling up after July 29th. Each day of the roll-out, we will listen, learn and update the experience for all Windows 10 users.
If you reserved your copy of Windows 10, we will notify you once our compatibility work confirms you will have a great experience, and Windows 10 has been downloaded on your system.
If your system is not ready yet for your upgrade to Windows 10, we will provide more details during the upgrade experience. In some cases, we will include contact information so you can follow up directly with an application provider or device manufacturer to learn more. For most upgrade incompatibilities, you may still choose to complete the upgrade, and find alternative compatible solutions in the Windows Store after you upgrade.
The rollout of Windows 10 is expected to take a couple of weeks as Microsoft anticipates one billion devices may update to the new OS.
Most of the information above applies to the average user of course, for advanced users there will likely be multiple ways to get a faster upgrade to Windows 10.