Windows 8.1 digital download will be released October 17, full retail launch October 18
Revised October 10th, 2013
Based on my recent conversation with a Microsoft Store support rep. you will be able to obtain the free upgrade to Windows 8.1 either by opening your browser and going directly to the Store’s web site or you can click on the Store tile on the “Start” screen. Some users may also receive a pop up notification.
"Windows 8.1 will begin rolling out worldwide as a free update for consumers on Windows 8 through the Windows Store. Windows 8.1 will also be available at retail and on new devices starting on October 18th by market."
No word yet about reviving the $40.00 upgrade offer, but it would be the smart thing to do in light of Windows 8 lackluster sales.
Windows 8.1 will be available to users via the Windows Store at 7:00 AM Eastern time on October 17. But I would hold off on attempting to install 8.1 until the immediate rush is over, which most likely can and will overload the servers. Also the smart thing to do is to create an image backup of Windows 8 just prior to installing 8.1, it’s your way back to sanity if something should go wrong.