Consumers looking to install Windows 7 on their current computers are now out of luck, as Microsoft has quietly discontinued the sale of the operating system as of October 30, 2013. The end of sales for PCs with Windows preinstalled will be on October 30, 2014, meaning you have less than a year to snatch up a desktop or laptop with Windows 7 preinstalled.

"End of sales refers to the date when a particular version of Windows is no longer shipped to retailers or Original Equipment Manufacturers (OEMs)," states Microsoft's lifecycle chart. "Examples of OEMs are Dell and Toshiba—PC manufacturers who often preinstall Windows software. When a version of Windows reaches its end of sales date, it's a good time to think about upgrading."

Computerworld points out that Microsoft's end-of-retail-sales date is a meaningless deadline, as many online retailers will continue to sell the software long after Microsoft pulls the plug. Although Microsoft itself has pulled Windows 7 from its virtual shelves, Amazon remains stocked full of various versions of Windows 7, as does tech specialist Newegg. Even some of Newegg's partners still carry Windows Vista and the current thorn in Microsoft's side, Windows XP.

"When Microsoft launches a new version of Windows, we will continue to allow OEMs to sell PCs preinstalled with the previous version for up to two years after the launch date of the new version," states Microsoft's lifecycle chart. "Certain OEM versions of Windows products include downgrade rights. Downgrade rights make it possible to use a previous version of Windows instead of the licensed software preinstalled on a new PC."

According to the chart, Windows XP exited the retail space on June 30, 2008, and was no longer licensed to OEMs on October 22, 2010. Windows Vista was discontinued in stores on October 22, 2010, and no longer sold to OEMs on October 22, 2011. Windows 8 won't be sold in stores beginning October 31, 2014, replaced by the current Windows 8.1, which launched on October 18, 2013.

The discontinuation of Windows 7 at retail feels like the end of an era. Like Windows XP, Microsoft may have a hard time shaking customers off the Windows 7 platform, as it has remained a solid, dependable platform since its introduction back in October 2009. Many Windows XP users feel the same way about their old operating system despite Microsoft putting pressure on them to upgrade. Eventually, Microsoft may have to do the same with Windows 7 users.