Apple’s retail stores, boosted by strong demand for iPads and Macs, are helping the tech giant intensify its assault on Microsoft, according to “TheStreet” (http://macosg.me/2/nh).

In a note to clients, Charlie Wolf, an analyst at Needham & Company, says that, that during the June quarter, Windows users purchased half of the 677,000 Macs sold in the stores. This represented over 20% of the estimated number of Windows users who switched to a Mac during the quarter, he says.

Windows users purchased half of the 606,000 Macs sold in the stores during Apple’s prior quarter and Needham estimates that, since 2004, more than 18 million Windows users have switched to a Mac. Apparently, Apple stores have played a key role in this effort.

“One of Apple’s initial reasons for opening Apple stores was to spotlight the Mac, which had virtually no retail visibility,” Wolf told “TheStreet.” “With an installed base that has more than doubled in the past five years, the Mac has gone mainstream with many consumer electronic chains now selling the Mac both here and abroad.”