Microsoft claims to have shipped 240 million Windows 7 licences in the first year of availability.
Windows 7 has "exceeded expectations", according to Gavriella Schuster, general manager of Windows Product Management.
"People from the very beginning have had an optimistic forecast. I actually felt in the beginning we needed to temper expectations a bit, but a year later, we're on track," she said in a blog post.
"We're right where we thought we would be. It's been a good year. It's a year to celebrate."
Shuster explained that Microsoft had released Windows 7 during a serious economic downturn, which had led to concerns at Redmond.
"We were in such a bad place economically. I didn't know how that was going to play out. I was nervous," she said. "But I feel really good about how it's all turned out."
Some enterprises were reluctant to upgrade systems during the downturn, especially when they were so entrenched in their use of current operating systems, making a move to the updated operating system unlikely, Shuster said.
However, the upgrade to Windows 7 remains firmly in enterprise mindsets, according to Microsoft, and is one of the main three projects expected to take place this year.
"The primary win - the reason why Windows 7 is so successful - is the phenomenal engineering effort. We delivered what we said we were going to deliver, when we said we would deliver it, with very high quality," said Shuster.
Microsoft claims that Windows 7 has 17 per cent of the global operating system market, and is on 93 per cent of all recently released consumer PCs.
Windows 7 users are four times more likely to recommend the operating system to friends and colleagues than they were this time last year, the company said, and the software enjoys a user satisfaction rate of 94 per cent.
Around 90 per cent of enterprises have upgraded, or are planning to upgrade, to the operating system this year, according to Microsoft, saving as much as $140 (£90) per PC per year.
Microsoft will continue to push Windows 7 over the next 12 months, Schuster added, and will increase its focus on the enterprise market. "It is very important. Enterprise is over half of our Windows revenue," she said.
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