The popular Linux platform was never considered, he said. "We would never look at Linux for something like this. It just doesn't scale to these levels."

British music retailer HMV is using a Microsoft application to sell music online. HMV is pleased with the price-performance, said David Cameron, head of software development at HMV Digital. The Windows system permits easy scaling, he said.

Cameron acknowledged that the ubiquity of Windows systems as a customer interface to its digital service weighed into the decision, but it was not the only factor.

"It's not just the Windows platform that the customers are using, it's all the DRM [digital rights management] technology ''' it's the whole environment that we're talking about here," Cameron said.

Microsoft also has been more accommodating in providing access to its handheld technologies than Apple has been with the iPod, according to Cameron.