The long, slow march toward end-of-life of Microsoft's currently most popular operating system is underway.

As of October 30, 2013, Microsoft ceased selling boxed copies of Windows 7 at retail. (ZDNet's Ed Bott posted back in April of this year about the pending October 30 cut-off date , but a few stories have popped up this week about it, so this is just a reminder.)

This October 30 cut-off date doesn't mean that OEMs or retailers are no longer selling PCs with Windows 7 preloaded. I can verify after a trip earlier this week to the Datavision computer store in New York (as part of my ongoing hunt for a new Windows PC) that there are plenty of Windows 7 PCs still for sale. OEMs can continue to sell PCs preloaded with Windows 7 until October 30, 2014.

Update (December 10): Microsoft is now saying it goofed in publishing the end of preload date being October 30, 2014 . Instead, that date has yet to be determined, the Softies claim.

Microsoft's explanation of what these dates mean, via its Windows Lifecycle Support Page:

"Note that when the retail software product reaches its end of sales date, it can still be purchased through OEMs (the company that made your PC) until it reaches the end of sales date for PCs with Windows preinstalled."

Mainstream (free, Microsoft-provided) support for Windows 7 with Service Pack 1 installed isn't expiring until January 13, 2015. Microsoft will continue to provide security fixes for Windows 7 for free until the end of extended support, which is January 14, 2020 -- unless Microsoft ends up extending that support date, as it did with Windows XP.

If you're in the market for a new Windows 7 PC, Bott posted earlier this year about where you'd be most likely to find one .

Users purchasing Windows 8.1 Pro also have downgrade rights to Windows 7 Pro. The Frequently Asked Questions FAQ document about downgrade rights is here.

Update: Speaking of end-of-support dates, there were a few reports this week about the Chinese government supposedly requesting an extension of Windows XP's planned end-of-support date of April 2014.

Microsoft's official response to this request (via a company spokesperson) is no.

The long version of that statement:

"Microsoft works in partnership with industry and government in China to help create an environment that encourages entrepreneurship, creativity and innovation through the protection of intellectual property, as well as assisting in software legalization efforts in line with the nation’s policy priorities. We have seen great improvement in the adoption of genuine operating systems, productivity software and apps, as well as movement to cloud services, as a result of these efforts and we look forward to continued progress. Microsoft is committed to working with end-users, businesses and governments in China to migrate their systems to a modern OS that better protects against security threats and is designed for modern work and life usage scenarios.

"Every Windows product has a lifecycle, which begins when it is released and ends when it is no longer supported. For Windows XP, this lasted more than a decade. Customers will still be able to use Windows XP, but as a reminder, after April 8, 2014, Windows XP users will no longer receive new security updates, non-security hotfixes, free or paid assisted support options, or online technical content updates from Microsoft. We are very glad to see a great number of customers in China and all over the world obtaining tangible benefits of modernizing their IT investments from dramatically enhanced security, broad device choice to meet the needs of a mobile workforce, higher user productivity, and lower total cost of ownership by future-proofing their IT investments through deploying Windows 8."