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"which might seem a bit cheeky from the holder of a trademark on the word Windows."
Oh please. If they had a trademark for Windows in the context of bits of colourless transparent glass commonly found in houses you might have a point but they don't they have a trademark for windows in the context of computer software. Similarly if Apple were applying for a trademark for AppStore in the context of Dogfood I doubt anyone would care but they aren't they are applying for it in the context of a store which sells apps.