For the first time, Microsoft has topped $100 billion in revenue.

Wall Street analysts have been swooning with delight, with at least one predicting the company will soon hit $1 trillion in market cap.

Still, Microsoft hasn't shown many signs of shoring up its obvious weaknesses.

CEO Satya Nadella has found a way to make those weaknesses a nonissue, by keeping Microsoft's most important customers — businesses — happy and locked in.

For the first time, Microsoft has topped $100 billion in revenue.

When Microsoft reported earnings on Thursday, it was a feast for the bulls, as it showed record-breaking annual revenue of $110.4 billion, a 21% jump in operating income of $35.1 billion, and total net profits of $16.6 billion.

By Friday morning, analysts were swooning with delight.

"The underlying strength, led by cloud and intelligent edge adoption, is expected to continue throughout the year," Christopher Eberle of Instinet wrote. Eberle noted that these were the best company-wide profit margins since 2014 and concluded that there was "not a lot for the bears to sink their claws into."

Keith Weiss of Morgan Stanley went further, predicting the stock would soar to a $1 trillion market cap. "Solid 4Q18 results keep MSFT on track to $1 trillion," he wrote, raising his price target to $130.

RBC's Ross MacMillan, who raised his target for the stock to $115, looked at Microsoft's commercial business — the products it sells to businesses — and wrote that it's "hard to see what stops the momentum."

But buried in all this wonderfulness was this tidbit: The only part of Microsoft's business that shrank was Windows licensing for consumer PCs. Microsoft reported that Windows "OEM non-Pro revenue declined 3%, slightly below the consumer PC market, driven by continued pressure in the entry-level price category."

Windows is both sickly and strong

A few years ago, right before Satya Nadella took over as CEO, Microsoft and its mobile operating systems were being surpassed by Apple iOS and Android. Missing the boat with smartphones seemed to hurt the Windows business catastrophically, perhaps even fatally.

Nadella's predecessor, Steve Ballmer, tried to fix it — too much, too late — by buying Microsoft's main Windows Phone supplier, Nokia. But when Nadella took the reins not too long after, he did an about-face.

Instead of doubling down on protectionist strategies, he went high, all the way to the cloud. In 2015, he tucked consumer Windows into a business unit called "More Personal Computing," which also includes businesses like the Xbox console and the Surface PC. It includes ad revenue from Bing, as well, which has risen alongside use of Windows 10.

In this way, he sort of tucked the sickly Windows business out of view.

And he capped it off just over a month ago, when the company announced that the longtime Windows executive Terry Myerson was out. In his place is the leader of Microsoft Office, Rajesh Jha, who will control a new group encompassing both Windows and Office.

Fast-forward to the end of Microsoft's fiscal 2018, and that shrinking Windows business doesn't matter, like a gnat in a windstorm.

Windows products for business users have been selling well, including Windows Pro, enterprise Windows licenses, and Surface PC. And selling Windows to business customers means Microsoft also gets to sell all kinds of extra, high-margin cloud services to businesses too, such as security, like Windows Defender, or Software Assurance, a support contract for businesses.

Nadella goes high, to the cloud

Microsoft has always used Windows as a way to sell other products. But under Nadella, Microsoft flipped this approach on its head. Instead of leading with Windows, it now leads with Office 365, which has become the sticky product that keeps people in Microsoft sphere. This, even though Office 365 is available for just about every device under the sun.

Microsoft In fact, a year ago, Microsoft bundled Office 365, Windows, and security products together for businesses in a package called Microsoft 365. That combination has become "a multibillion-dollar business," Nadella told analysts on the quarterly conference call.

When enterprise IT departments use Office 365, their enterprise contracts also encourage them to try Microsoft Azure, Microsoft's cloud competitor to Amazon Web Services, where they rent capacity from Microsoft's data center to run their apps. Azure is still the second-place cloud behind Amazon Web Services, but it is doing well and growing.

"In FY18, we closed a record number of multimillion-dollar commercial cloud agreements and more than doubled the number of $10 million-plus Azure agreements," Nadella said.

Microsoft still doesn't report Azure revenue in dollar amounts, this time saying only that Azure revenue grew 89% over the year-ago quarter. Counting all things cloud sold to businesses, however, Microsoft brought in $23 billion in revenue, its gross margin expanding to 57%.

And this is now the core of what Microsoft does.

So instead of talking about Microsoft's continued absence in mobile, or its ongoing decline in consumer PCs, the company is soaring toward $1 trillion on the back of the cloud.