The company said Tuesday the problem occurred when previously released updates were still being installed while the Windows RT 8.1 update was being downloaded. For about 1 of 1,000 Surface RT owners who downloaded the 8.1 update, that caused the machine to shut down and become inoperable.
Microsoft has offered a way to revive the unit and complete the update using a USB drive. The solution requires using a separate computer.
On Tuesday, Microsoft also began selling its latest models, Surface 2 and Surface Pro 2.
Online: Windows 8.1 RT recovery steps »