Abstract: The present invention is a method and apparatus for switching first and second tasks in an operating system. The first and second tasks each have first and second traditional states and first and second extended states, in a processing unit. The method comprises: (a) saving the first traditional and extended states from the processing unit to a buffer; (b) updating the buffer by replacing the first extended state by the second extended state; and (c) restoring the first traditional state and the second extended state in the processing unit from the updated buffer.