Microsoft was deemed to have a monopoly in "Intel-compatible PC operating systems". An ARM tablet is not in this market; Microsoft has no monopoly in this market; Microsoft cannot be fined for abusing monopoly power in this market as it does not have monopoly power. They are free as Apple or Android to allow or disallow software on that platform.

IANAL.

If they use the popularity of Windows to gain share on ARM, they are effectively abusing their "Intel-compatible PC operating systems" one.

Having a strong brand is not an abuse of monopoly power. That's ridiculous.

An abuse of their monopoly power would be something like denying Windows licenses to PC makers unless they agree to exclusively produce Windows 8 ARM tablets. There needs to be a leverage of the monopoly power in doing something anticompetitive for there to be an illegal act.

> Having a strong brand is not an abuse of monopoly power. That's ridiculous.

I was not speaking of brand, but OEM agreements. IIRC, if the OEM posts "X recommends Windows Y" on every product page, they get a better license price.

> ...would be something like denying Windows licenses to PC makers unless they agree to exclusively produce Windows 8 ARM tablets

Or differentiating their Android patent licenses according to the licensee's willingness to manufacture Windows Phone devices too. Or only licensing Windows 8 to ARM tablets that can never run anything else.

I don't see how your two examples show leverage of the Intel PC monopoly.

I'm pretty sure you can't say that so categorically. If you can distort the market (specifically: have a monopoly), then in principle any means you use to do so might be illegal. Using a brand might qualify - at least I'm not aware of any specific exceptions that would exclude them.