On the 18-month anniversary of the launch of Windows 7, Microsoft reported Friday that its flagship operating system has sold more than 350 million licenses. Its market share, though, still pales in comparison to Windows XP.

In a blog post, the company emphasized the business cases for companies to transition over to the new operating system, and launched a dedicated customer showcase page to highlight customers like Tsingtao, Energizer, and the City of Miami, and their success stories with their transitions over to Windows 7.

The numbers for Windows 7 at the 18-month mark show that Microsoft's sales of Windows 7 have plateaued somewhat; at the one-year mark, Microsoft announced that 240 million licenses of Windows 7 had been sold. Microsoft did not release sales figures for the first six months of Windows 7.

On the other hand, the market share of Windows 7 has steadily increased; according to Net Applications, the market share of Windows 7 now stands at 24.17 percent for the month of March, inching ahead a percentage point or two since May 2010, when it recorded a 12.68 percent share. Windows 7 doesn't appear like it will upend Windows XP anytime soon, however; WinXP's market share still stands at 54.39 percent of the market, and dipped only about a percentage point in the first three months of 2011.

Windows Vista, however, has steadily if slowly declined to 10.56 percent.

Full story: PC Magazine