The company's policies for shutting off sales to retailers and shipping licenses to OEMS (original equipment manufacturers) are posted on its site, which was recently updated to show that Windows 7's "retail end of sales" date was Oct. 30.

The next deadline, marked as "End of sales for PCs with Windows preinstalled," will be Oct. 30, 2014, less than a year away.

Microsoft's practice, first defined in 2010, is to stop selling an older operating system in retail one year after the launch of its successor, and halt delivery of the previous Windows edition to OEMs two years after a new version launches. The company shipped Windows 8, Windows 7's replacement, in October 2012.

As recently as late September, the last time Computerworld cited the online resource, Microsoft had not filled in the deadlines for Windows 7. At the time, Computerworld said that the end-of-October dates were the most likely.

A check of Microsoft's own online store showed that the company has pulled Windows 7 from those virtual shelves.

In practical terms, the end-of-retail-sales date has been an artificial and largely meaningless deadline, as online retailers have continued to sell packaged copies, sometimes for years, by restocking through distributors which squirreled away older editions.