http://blogs.windows.com/bloggingwindows/2015/07/02/windows-10-preparing-to-upgrade-one-billion-devices/
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.
There is no need to "reserve" anything. It is merely marketing on the part of MS to "encourage" users to upgrade AND help them spread out the load on their servers.. They will be happy to upgrade any qualifying OS during the first year for free and it will remain free for the life of the device when it is released on July 29 *
You gain nothing by "reserving" other than giving Microsoft an email address to spam you at. You will not get it any sooner, nor will there be any other advantage. In FACT, if you reserve you may get it later as this statement from Microsoft explains
Your data should be seamlessly updated but as usual if you value your data BACK IT UP
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You can read more about it here http://windowssecrets.com/top-story/what-you-should-know-about-the-win10-launch/
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Windows 10 FAQS http://www.microsoft.com/en-us/windows/windows-10-faq Windows 10 features http://www.microsoft.com/en-us/windows/featuresWin 10 Specs http://www.microsoft.com/en-us/windows/windows-10-specifications
How to upgrade http://www.microsoft.com/en-us/windows/windows-10-upgrade
Upgrade paths http://www.askvg.com/windows-10-upgrade-paths-and-things-to-know-before-upgrading/
What you should know about the Win10 launch
http://windowssecrets.com/top-story/what-you-should-know-about-the-win10-launch/
Upgrade to Windows 10 for free http://www.microsoft.com/en-us/windows/windows-10-upgrade
Hi Chagand,
If you have installed the KB 3035583, you will get the Windows 10 icon.
Here is a link for reference:
Update installs Get Windows 10 app in Windows 8.1 and Windows 7 SP1
https://support.microsoft.com/en-us/kb/3035583
For more information about Windows 10, we could refer to the link as ZigZag posted.
Best regards