Microsoft has ended retail sales for its Windows 7 and 8 operating systems, CIO Today reported. Until the mid-2015 release of the new Windows 10, customers can now only purchase Windows 8.1; Windows 7 Professional, meanwhile, remains available through downgrade rights.

Original equipment manufacturers can still sell PCs with pre-installed versions of Windows 8 and Windows 7 Professional, the technology site reported. However, Windows 7 Home Basic, Home Premium and Ultimate can no longer be offered as of Oct. 31.

"Microsoft has not yet scheduled a release date for Windows 10, although it's expected to come out some time after the company's next Build Developer Conference, which is set for April 29 through May 1 of next year," CIO Today detailed. "Computer-savvy users will be able to take 10 for a test drive earlier, though, through Microsoft's new Windows Insider Program.

The software giant's decision might be "frightening" to some Windows users, InformationWeek suggested.

"To PC shoppers who want a Start menu or aren't enamored with touchscreens, (the lack of Windows 7) could be a scary thought," the publication warned. In the move from Windows 7 to Windows 8, Microsoft had done away with the Start icon - a stalwart since the revolutionary Windows 95 - and transitioned to a more tablet and mobile-friendly touchscreen surface.

InformationWeek pointed out that "new Windows 7 PCs won't disappear" on Nov. 1. "OEMs such as HP and Dell won't be able to purchase Windows 7 Home Basic, Home Premium, or Ultimate licenses after Friday," it said "They'll be allowed to sell their remaining stock of Windows 7 machines, however."

Given that Microsoft has promised to announce an end to OEM sales of Windows 7 Professional at least a year in advance, "most manufacturers will also continue to offer business-oriented computers with Windows 7 Professional until at least late 2015," InformationWeek added.

Microsoft Windows 7 today has a market share of about 53 percent of the PC market, according to ZDNet. Windows 8 and 8.1 account for only 16.8 percent, less than "the antique XP," which still commands 17.2 percent.