Windows 7 continued to bolster Microsoft's bottom line in the most recent quarter, with Microsoft reporting net income of $4 billion on record quarterly revenues of $14.5 billion for the time period. Those figures are up significantly year over year—income jumped 35 percent—and Microsoft credited continued strong sales of Windows 7 for the positive performance.

"Windows 7 continues to be a growth engine, but we also saw strong growth in other areas like Bing search, Xbox Live, and our emerging cloud services," said Microsoft Chief Financial Officer Peter Klein. "Our record third-quarter revenue along with continued rigor on cost management resulted in exceptional growth."

Microsoft's revenues would have been even higher, but the company deferred $305 million in revenues related to the Microsoft Office 2010 Technology Guarantee program. Those revenues will be realized in the current quarter, but if Microsoft had reported them for the previous quarter, its revenues for that time period would have $14.81 billion.

According to Microsoft, Windows 7 remains a sales phenomenon. Just five months after its release, the OS is already in use on over 10 percent of all PCs worldwide, making it the fastest-selling OS release in PC history. Revenues related to the Windows division were up 28 percent year-over-year, thanks to Windows 7, to $4.4 billion, the company noted. And Windows division profits jumped to $3.06 billion, from $2.3 billion a year ago.

Windows 7 is driving a PC sales renaissance, Microsoft said, with industry growth pegged at 25 percent. Best of all, perhaps, its corporate customers are now jumping on board: Microsoft says that business PC sales jumped 14 percent in the quarter.

Though Microsoft exceeded analyst's expectations for the quarter—the company earned 45 cents a share in the quarter, better than the 42 cents a share forecast by analysts—stock in the software giant fell 4 percent in after-hours trading Thursday. And while the illogical fluctuations of tech stocks are often hard to gauge, this time there was a pretty obvious reason: According to Standard and Poor's, Microsoft's old rival Apple this week surpassed Microsoft's market cap, becoming the second-largest company listed on the S&P 500 after Exxon-Mobile.

Microsoft argues that this rating was unfair, since the market cap figures count only 87 percent of a company's value (for reasons that are almost too complex to contemplate, let alone explain). If all of a company's value is considered, Microsoft is still considerably bigger than Apple. But S&P is sticking by its rating: Its market cap rating is calculated the same way it's always been calculated, and Apple is now bigger according to that calculation. "On a full basis, Microsoft is still larger \\[than Apple\\]," S&P Senior Index Analyst Howard Silverblatt admitted. "\\[But\\] Apple is bigger on a float basis, which is what the index is."