Windows Phone 7's SD card problem: Not Microsoft's fault

Device makers are to blame for adding removable storage to an OS that was not designed to support it

I am by no means a fan of Windows Phone 7, and I don't see a coherent mobile strategy at Micosoft. But the current brouhaha over Windows Phone 7 devices reformatting MicroSD cards into a proprietary format is misguided. This is not some boneheaded Microsoft move. Microsoft has been very clear on the matter for months: Windows Phone 7 doesn't support removable media cards.

Microsoft decided some time ago -- and has been forthright about this for months -- that the device would be like Apple's iPhone in that its storage would be closed, not like BlackBerry or Android devices.

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In fact, Microsoft said for some time that its Windows Phone 7 hardware requirements wouldn't even allow expandable storage, to ensure the device's data integrity. Somewhere along the way, some of the device makers decided to let their devices' storages be expandable anyhow, and they chose to use the MicroSD format for that. Microsoft then created rules on how that would work, including tying the storage to a specific smartphone to make it an extension of that device.

The use of MicroSD was misguided on the device makers' end. Sure, they now get to check off the box that says "supports expandable storage" in the marketing cards at the store. But by using a hardware format that people expect to be readable by other devices, their customers understandably believe that the removable storage in their Windows Phone 7 devices was the same as any other MicroSD card. It isn't and never was meant to be. The device makers knew that and should have used a different format or had neon warnings on the device's packaging to that effect.

You can argue whether Windows Phone 7 devices (or iPhones, for that matter) should support standard removable-media formats. But that isn't the point. In this case, Windows Phone 7 is doing exactly what it was designed to do, and what Microsoft said it would do all along.

If Microsoft deserves any blame, it's for relaxing its original "no external storage" rule and letting its hardware partners confuse customers by using a nonproprietary physical standard for a proprietary purpose. I can see why customers are confiused and angry. But blame HTC, LG, and Samsung for this mess. It's their fault.

This article, "Windows Phone 7's SD card problem: Not Microsoft's fault," was originally published at Read more of Gruman et al.'s Mobile Edge blog and follow the latest developments in mobile technology at

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