Apr 23, 2011 06:52 GMT  ·  By

Windows 7’s unaltered momentum has pushed the operating system to a new milestone dwarfing the success of all other platform releases even further. Microsoft reveals that Windows 7 sales have hit the 350 million mark at a year and a half since general availability, an impressive accomplishment, by any standards.

Between January and April 2011, over 50 million copies of the OS went to customers worldwide. In the three months preceding them, 60 million licenses were sold, according to statistics from the software giant.

“Customers having a positive and productive experience with Windows 7 is also an important measure,” notes Microsoft’s Brandon LeBlanc.

“Analyst firms like IDC estimate that more than 90% of businesses are currently in progress with their Windows 7 migrations. And we’ve seen that companies who have deployed Windows 7 save an average of $140 per PC per year – showing a 131% return on investment in just more than 12 months.”

Perhaps the biggest measure of Windows 7’s success in direct relation to license sales, is that over 300 million of copies were purchased ahead of the release of Service Pack 1.

I remember a time when customers, businesses especially, but it was starting to rub off on end users as well, would only start considering upgrades to a new Windows iteration after the release of SP1.

Windows 7 broke the mold, showing that customers care less about upgrades and more about the quality of a product when deciding whether to adopt it or not. And Windows 7 has been rock solid from day one, delivering top performance and reliability.

“We’ve done a lot in the last 18 months that improves upon the experience people have on their PCs with Windows 7,” LeBlanc added.

“We launched Windows Live Wave 4 (which included Windows Live Essentials 2011 and enhancements to Hotmail), released the first service pack for Windows 7, and recently launched Internet Explorer 9.

“And we’re hard at work on further innovation for Windows. At CES this year we announced the next version of Windows will support System on a Chip (SoC) and last week at MIX11 we released the first platform preview to developers for Internet Explorer 10.”

Windows 7 SP1 RTM and Windows Server 2008 R2 SP1 RTM are available for download here.