At a New York City press conference intended to introduce some new features for his enterprise software company Salesforce (NYSE: CRM), CEO Marc Benioff said that Microsoft’s (Nasdaq: MSFT) upcoming Windows 8 operating system will be “the end of Windows” and that “Windows is irrelevant.”

Benioff was attending the Cloudforce show in Manhattan after an announcement made Friday morning said his company was expanding its social analytics features with 20 social analytics partnerships. According to a report by VentureBeat, Benioff, who is never averse to stirring up a new tech entrepreneur feud, started criticizing the radically redesigned Microsoft operating system.

Salesforce, like its rival Oracle (Nasdaq: ORCL), specializes in selling customer relationship management (CRM) services to businesses, so the concern over Microsoft’s performance with Windows 8 is understandable. As the de facto standard for the vast majority of offices, the Windows operating system has been able to sit comfortably atop the market through many of the recent revolutions in the tech and consumer electronics industry.

As the shift towards a colorful, touch-screen friendly design for Windows 8 shows, however, even Microsoft is feeling the pinch of a weak economy and the growing market presence of rivals like Google (Nasdaq: GOOG) and Apple (Nasdaq: AAPL). So the question inevitably became: will businesses accept the new and possibly improved version of Windows if they have to retrain so many legions of workers?

Hopefully not, according to Benioff, who spoke candidly about a conversation he had with a Salesforce client who said flatly that she was not planning to transition to Windows 8, which launches next week on Oct. 26.

Instead, Benioff said the most important developments in personal computing won’t come in the form of desktop computers; instead, people will focus on their smartphones and tablets.

While Windows 8 was clearly developed with tablets in mind, Benioff argued that the dramatic changes to the operating system itself were an admission that Windows 8 simply isn’t important.

“Windows 8 is the gambit — will [CIOs] upgrade, or will they do something else?” Benioff asked. Really, he argued, businesses only upgraded to Windows 7 because they were required to.

As the CEO of a major cloud-based software developer, Benioff is clearly hoping that these sorts of hardware and software quibbles between large companies like Apple and Google will eventually fade away as their core services are eclipsed by cloud computing; even Microsoft has been preparing for the shift to the cloud.

“It’s the end of Windows,” Benioff concluded. “Windows is irrelevant.”

Shares in Salesforce dropped by nearly three-quarters of a percent on Friday, closing at $149.01. Microsoft fell by a slightly larger margin, closing at $28.64.