Last month, shares of Microsoft (NASDAQ:MSFT) dropped following the release of its second-quarter financial report. Microsoft's earnings per share and revenue came in line with analyst expectations, but its Windows business showed signs of weakness.

Microsoft has outperformed the broader market for most of the last two years, but over the last month, shares have fallen nearly 6%.

Still, Microsoft could be poised for a rally. Below are three reasons why Microsoft's stock could rise. It should be noted, however, that even if all three scenarios come to pass, Microsoft's stock could still decline -- a general market crash could weigh on shares even if Microsoft's business is booming. Nevertheless, shareholders should welcome the following possibilities.

Windows 10 rejuvenates the PC
Although Microsoft's business isn't as dependent on Windows as it was in the past, the operating system is still important to Microsoft's success. Unfortunately, Windows appears increasingly irrelevant, and Microsoft's ability to monetize it going forward is a legitimate concern: Last quarter, Windows revenue declined 13% on annual basis.

But Windows could be poised for turnaround -- both as a business and as a platform.

Later this year, Microsoft will launch Windows 10, the next version of its operating system. Compared to its predecessor, Windows 8, Windows 10 appears to be a far better product, with a bevy of new features that significantly improve the desktop experience.

For the first year, consumers with PCs running Windows 7 or Windows 8 will be able to upgrade for free, which will likely cost Microsoft some revenue, at least in the short term. But enterprise customers will have to pay, as will those who don't upgrade in a timely fashion. More important could be a potential wave of new PC sales sparked by a strong Windows 10 reception, as those who may have held off on upgrading decide to purchase a new PC.

It continues to add cloud subscribers
In contrast to Windows, Microsoft's cloud businesses have been booming. Last quarter, commercial cloud revenue rose 114% from the same quarter last year. Microsoft's Office 365 -- its subscription-based Office service -- now has 9.2 million subscribers, and its commercial cloud has an annual run rate of $5.5 billion.

But Microsoft could just be getting started.

Bullish Microsoft investors -- notably, the hedge fund ValueAct -- have argued for Microsoft in the past on its potential to become a cloud computing giant, perhaps the biggest in the world. In addition to Office 365, Microsoft has a number of other cloud computing products, including Dynamics CRM and Microsoft Azure.

If these businesses continue to grow rapidly, they could eventually form the backbone of Microsoft's business, completely overshadowing Windows. Microsoft faces a number of fierce competitors in the space, but it's been successful thus far.

Its mobile efforts show some signs of success
Microsoft is, for all practical purposes, irrelevant when it comes to mobile computing. Windows Phone is the third most common mobile operating system, but it's a distant third -- both Android and iOS are many times more popular; Windows Phone's global market share hovers in the low single-digits. Windows tablets have been a bit more successful, but are still vastly outnumbered by Android tablets and the iPad.

At this point, it would be quite unrealistic to expect Microsoft to emerge as a dominant player in mobile computing. Still, any progress would be welcomed.

Investors received some signs of encouragement last month, though they are admittedly faint. In the second quarter, Microsoft's Surface-related revenue rose 24% annually, up to $1.1 billion. Handset revenue declined on a sequential basis (11%), but unit sales improved to 10.5 million.

So long as Windows remains in demand, and its cloud services are seeing strong adoption, Microsoft may be able to survive in spite of its mobile irrelevance. But stronger adoption of Windows mobile devices would benefit the Windows platform and Microsoft's business.

Sam Mattera has no position in any stocks mentioned. The Motley Fool recommends Apple. The Motley Fool owns shares of Apple. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.