With its Q2 results today, Microsoft (NASDAQ: MSFT) reported its best quarter in history in terms of revenue, bringing in nearly $21.46 billion, even though that figure was slightly under the average analyst estimate of $21.53 billion. Net income, meanwhile, was $6.4 billion ($0.76 per diluted share), a slight beat over the $0.75 the market expected.

The quarter's revenue figure represented a nearly 3% improvement over Q2 2012, while the bottom-line number dropped by almost 4% in the same time frame.

Not surprisingly, Microsoft's key Windows unit was the driver of revenue growth, increasing its take 24% on a year-over-year basis to $5.9 billion. Windows 8 went into general release during the quarter.

The results of other units were mixed. The server and tools division grew its top line 9% to $5.2 billion, and online services advanced 11% to $869 million, but the business division and the entertainment and devices unit both suffered declines. Revenues for the two were, respectively, down 10% to $5.7 billion, and 11% lower at $3.8 billion.