Microsoft’s AI assistant Copilot can ignore your chosen web browser and display links through Edge instead, according to research published July 14 by Mozilla. The finding, part of the Over The Edge 2.0 report, reveals that the long-running dispute over browser defaults has shifted from operating-system menus to the AI tools that increasingly stand between you and the web.

What Mozilla discovered

The study, commissioned by Mozilla and conducted by deceptive-design specialists Dr. Harry Brignull and Cennydd Bowles, tested Windows 10 and Windows 11 experiences in the United States, India, the United Kingdom and Germany. The headline conclusion: when Copilot provides a link—whether you asked it to compare products, summarize a topic, or find a service—that link may open inside an Edge-rendered panel, entirely ignoring whichever browser you had set as the default.

That’s not an isolated quirk. The researchers documented a pattern of design choices that favor Edge at multiple touchpoints:

  • Windows Search and Widgets can open web results in Edge even when Firefox or Chrome is the default.
  • Edge displays its own promotional messaging when you visit Google’s Chrome download page.
  • Windows continues prompting users to adopt Edge after another browser has been selected.
  • Windows Backup may not consistently preserve your browser preference during a Windows 10 to Windows 11 migration, so the new installation silently falls back to Edge.

Mozilla is not a neutral observer—it builds Firefox, a direct competitor—but the report’s value lies in the concrete user journeys it documents. The migration issue is especially troubling for anyone preparing to leave Windows 10. If the backup and restore process doesn’t reinstall your chosen browser, Edge simply takes over, and you might not immediately notice the switch.

The report’s most striking evidence isn’t that Microsoft integrates Edge into Windows; it’s that the company has already created a less aggressive experience in regions where regulation requires one. In Germany, which was used as the representative European Economic Area market, several design patterns present in the U.S. and India were absent or toned down. Copilot-related data controls that defaulted to “on” in the U.S. and India defaulted to “off” in the EEA and the U.K.

The difference traces back to the European Union’s Digital Markets Act. In response, Microsoft has already allowed Edge to be uninstalled, made Windows web-search work with third-party providers, and honored default-browser selections more consistently. Those changes demonstrate that deep Edge integration is a business decision, not a technical necessity. Microsoft simply chooses not to deploy those same choice mechanisms worldwide.

What this means for you

If you’re an everyday Windows user, you may not notice the sleight of hand, but your experience becomes fragmented. Links from Copilot open in Edge, where your saved passwords, bookmarks, and extensions might not be available. The assistant that was supposed to simplify your workflow quietly pulls you into a different ecosystem.

If you’re an IT administrator, the stakes are higher. You might have standardized your organization on Chrome or Firefox, but Copilot, Windows Search, Widgets, and even links inside Outlook could bypass those policies. A default that works for email but not for the AI assistant your staff relies on is not a true system-wide default. Hard-won Group Policy settings that lock down browser choice are undermined by a side panel you may not have tested.

If you’re about to migrate from Windows 10, pay attention to the backup process. As Milestone 43% of Windows PCs in India were still on Windows 10 during the first quarter of 2026, with similar numbers in other markets. The report warns that a migration that fails to restore your browser application means Windows 11 will hand the keys to Edge. Before you start, verify that your backup includes not just your files and settings but also the installer for your preferred browser—or be prepared to reinstall it manually.

Developers and power users should note that this is not just about which icon you click. The panel in which Copilot displays content is effectively an Edge instance. That matters for scripted workflows, automated testing, and any tooling that expects web content to open in a specific, controlled environment.

How we got here

Browser default battles are almost as old as Windows itself. The 1990s antitrust case against Microsoft centered on Internet Explorer’s bundling. In the 2010s, Windows 10 used aggressive prompts to steer users toward Edge, and the company faced criticism for ignoring default-app settings during updates. The DMA forced some European concessions in 2023–2024, but those were never rolled out globally.

Now the fight has moved to a new layer. Copilot and similar assistants are becoming the primary interface for web tasks, placing an intelligent agent between the user and the raw browser engine. When you ask Copilot a question, you are not consciously choosing which browser to use—the assistant makes that decision for you. As Mozilla points out, if AI-driven self-preferencing goes unchecked, decisions made today could shape the digital landscape for the next decade.

What you can do right now

  • Audit your default behaviors. Don’t assume your default browser setting is respected. Test a link from Copilot, from a Widget, and from Windows Search. Note where each opens.
  • Copy links manually. When Copilot provides a useful result, right-click and copy the link, then paste it into your chosen browser. It’s a small friction, but it keeps you in control.
  • Use Copilot in a browser. Visit copilot.microsoft.com through Firefox or Chrome instead of the built-in taskbar panel. The web-based version respects your browser session.
  • For enterprise admins: use Group Policy Objects to enforce default browser associations and block Edge from overriding them. Microsoft’s own documentation outlines policies for managing Windows search and Widgets, but test them against Copilot on your specific Windows builds. Incorporate Copilot link behavior into your standard user acceptance testing before rolling out new Windows features.
  • Prepare for Windows 10 migrations. Before initiating a backup, note your browser and ensure the installer is saved to a location that will survive the transfer. After upgrading, immediately verify that your preferred browser is installed and set as the default. If not, reinstall it and check the association again.
  • Participate in the Windows Insider Program. Microsoft sometimes previews changes to default-app handling there. Early feedback can influence final builds.
  • Voice your concern. The report is aimed partly at regulators, but user feedback through the Feedback Hub and direct messages to Microsoft’s support channels can add weight, especially if you encounter specific, reproducible issues.

What to watch next

Mozilla is explicitly using the EEA experience as evidence that regulatory intervention works, and it’s pushing for those protections in every market, including India, which is currently exploring its own digital competition framework. If other browser makers and enterprise customers amplify the message, Microsoft might face renewed pressure to make Copilot, Search, and Widgets respect the system default globally.

In the near term, expect more AI assistants to blur the lines between desktop and web. The question isn’t just which browser you’ve pinned to your taskbar; it’s which assistant is deciding how you access the internet. Until Microsoft aligns Copilot’s behavior with the user’s stated preference, “default browser” will mean less than the Settings page suggests.