Microsoft announced record revenue of $14.5bn for the quarter ending 21 March, a 6% increase from the same period the year before.
The software firm reported operating income of $5.17bn and net income of $4.01bn, representing increases of 17% and 35% respectively compared with the same period the previous year.
"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 Peter Klein, chief financial officer at Microsoft.
Windows revenue was up 28%, compared with the same quarter a year earlier, driven by strong demand for Windows 7.
More than 10% of all PCs worldwide are running Windows 7 today, making Windows 7 by far the fastest-selling operating system in history, Microsoft said in a statement.
"Business customers are beginning to refresh their desktops and the momentum of Windows 7 continues to be strong," said Kevin Turner, chief operating officer at Microsoft.
"We are also seeing tremendous interest in our market-leading cloud services for business," he said.
Investors had predicted better sales in Microsoft's server division, and expected companies to have placed advance orders for more new software, analysts said.
Microsoft's share price was at $31.39 before the financial results were announced, but fell $1.15, or 3.7% to $30.24 in extended trading.