Microsoft is considered to hold monopoly power in the x86 PC operating system market. Any leverage of that monopoly to reduce competition in a different market

Microsoft is considered to hold monopoly power in the x86 PC operating system market. Any leverage of that monopoly to reduce competition in a different market would be a violation of antitrust laws. Forbidding manufacturers from entering into agreements to preinstall antivirus software, search toolbars, and other crapware they typically install as a condition of licensing Windows would be such a leverage of power. Thus, they are legally barred from taking your suggestion. IANAL