Opera has filed a complaint against Microsoft in Brazil, accusing the company of using "manipulative design tactics" to dominate the browser market and hinder competition. Opera's general counsel, Aaron McParlan, stated that Microsoft creates barriers for other browsers, such as excluding them from preinstallation opportunities and complicating the download process. The complaint highlights Microsoft's practices of overriding users' default browser preferences and using Windows features to promote Edge. Opera seeks remedies to allow PC manufacturers to preload alternative browsers and stop blocking downloads. Additionally, the complaint criticizes Microsoft's requirement for OEMs to deliver devices in S mode to receive rebates on Windows OS licenses. This action is part of Opera's broader strategy to challenge Microsoft's practices globally, including an appeal to EU courts regarding the classification of Edge under the Digital Markets Act. Opera has a history of raising concerns about Microsoft's browser practices, including a 2007 antitrust complaint that led to the creation of a browser ballot screen.