Worldwide PC demand grew more than expected in the second quarter, propelled in part by a phasing out of support for Microsoft Corp.'s /zigman2/quotes/207732364/composite MSFT +0.89% Windows 7 operating system, according to research firm International Data Corp. Sales of PCs rose 4.7% to 64.9 million units from the year ago quarter as supply shortages eased, IDC said. "With the January 2020 end of service (EOS) date for Windows 7 approaching, the market has entered the last leg of the Windows 7 to Windows 10 commercial migrations," said Linn Huang, IDC research vice president, in a statement. According to IDC, market share was 25.1% for Lenovo Group Ltd. /zigman2/quotes/205368244/delayed HK:992 +0.75% , 23.7% for HP Inc. /zigman2/quotes/203461582/composite HPQ +0.68% , 17.9% for Dell Technologies Inc. /zigman2/quotes/203822527/composite DELL +0.63% , 6.6% for Acer Group, and 6.3% for Apple Inc. /zigman2/quotes/202934861/composite AAPL +0.02% . Earlier Thursday, research firm Gartner reported a 1.5% rise in PC sales to just under 63 million units but Gartner does not include Chromebooks that run on Alphabet Inc.'s /zigman2/quotes/205453964/composite GOOG +0.40% /zigman2/quotes/202490156/composite GOOGL +0.35% operating system. Like IDC, Gartner attributed Windows 10 as a catalyst for growth.