If you rely on Windows Backup to migrate from an old PC to a new Windows 11 machine, there’s a good chance your carefully chosen default browser won’t survive the trip. Researchers commissioned by Mozilla have documented that restoring a Windows 10 backup onto Windows 11 can quietly reset the system default to Microsoft Edge — even when another browser was previously set as the default. The finding comes from the Over the Edge 2.0 report, published July 14, 2026, which catalogs a series of design choices in Windows that continue to steer users toward Edge.
This isn’t about a missing app after a restore. The problem is deeper: the migration process appears to discard the user’s prior default-browser association and fall back to Microsoft’s own browser, regardless of intent. For anyone planning a hardware refresh or finally retiring Windows 10 after its October 2025 end of support, that’s a practical warning worth heeding.
The Migration Trap: How a Backup Can Overwrite Your Choice
Researchers Harry Brignull and Cennydd Bowles ran a straightforward test for Mozilla. They set up a Windows 10 PC with a non-Edge browser installed and configured as the system default. They then backed up that machine using Windows Backup and restored the backup onto a clean Windows 11 installation. The third-party browser didn’t appear after the restore, and Edge had taken over the default-browser role.
Application migration isn’t magic. Windows Backup doesn’t promise to reinstall every Win32 program; many apps demand fresh licensing, compatibility checks, or separate deployment steps. But default protocol associations — which handler opens HTTP, HTTPS, HTML, and PDF links — are configuration data, not application binaries. Their loss creates a distinct outcome: a deliberate user setting vanishes, replaced by Microsoft’s preferred option without any prompt or notification.
The report calls this a “silent reset” of a past decision, and the term fits. A non-technical user performing a backup restore might never realize that their browser preference has been changed. They’ll simply start clicking links and find themselves in Edge, with no indication that Chrome, Firefox, or another browser used to be the default.
Crucially, the behavior isn’t uniform across regions. Mozilla’s testing spanned the United States, the United Kingdom, India, and Germany (used as a proxy for the European Economic Area). In Germany and the broader EEA, the backup test did not exhibit the same default reset — a consequence, the researchers say, of Microsoft’s compliance with the European Union’s Digital Markets Act. That geographic discrepancy is its own headline: a browser preference that travels intact in Berlin gets wiped in Boston.
Who This Affects — and Why It Matters
The impact ripples differently for home users, IT administrators, and anyone using Windows in a mixed-browser workplace.
Home users. If you’re planning to buy a new Windows 11 PC and rely on Windows Backup to move your settings, expect to check your default browser immediately after setup. The restore might bring over your desktop wallpaper, your taskbar pins, and your Edge favorites — but it could discard the association that tells your system to open links in Firefox or Chrome. For families, that means an unsuspecting relative could end up browsing in a different application, with different saved passwords, extensions, and bookmarks, without realizing a change occurred.
IT administrators. Anyone managing a Windows 10 retirement project or a fleet of refresh cycles should treat browser defaults as a configuration item, not a personal preference that will persist. If your organization standardizes on a non-Edge browser, don’t assume a user’s existing default will survive a Windows Backup migration. Plan to deploy and set the approved browser through Intune, Group Policy, Configuration Manager, or another endpoint management platform. Microsoft’s own Edge enterprise documentation exposes policies like DefaultBrowserSettingEnabled that let you control whether Edge checks or prompts to become the default — a lever you can use to lock down the experience.
There’s also a workflow integrity dimension. Many Copilot interactions, the report notes, can open links in Edge even when another browser is set as the system default. That’s not a bug in Copilot per se; Windows supports a microsoft-edge: URI scheme that launches Edge regardless of protocol associations. But for employees, a link opened from an AI assistant that lands in the wrong browser can split sessions, isolate passwords, bypass extension controls, and complicate conditional-access policies. The default-browser setting only governs standard http and https links. Microsoft can, and sometimes does, route other link types directly to Edge.
Users in regulated regions. If you’re inside the European Economic Area, DMA-mandated changes mean you’re less likely to encounter this backup reset. But Mozilla warns that some harmful patterns persist even there. For users outside the EEA, the full suite of Edge-steering behaviors remains active unless a future regulatory push changes the calculus.
How We Got Here: A Long Trail of Browser Choice Friction
Microsoft’s vigorous promotion of Edge isn’t new. What’s changed is the inventory of methods Mozilla has now cataloged. Over the Edge 2.0 identifies several categories of what its authors call deceptive design: visual interference (overlaying a large comparison ad when you visit Chrome’s download page in Edge), preselected options (making “Use recommended settings” the easy click), nagging (repeated prompts to switch back), and forced action (requiring extra clicks to keep a competitor as default).
Two years ago, an earlier Mozilla report covered similar tactics. Some of those have been softened, especially in Europe. In November 2023, Microsoft announced a set of Windows changes to comply with the DMA, including the ability to uninstall Edge, the preservation of existing default browser choices through Windows updates, and the removal of certain Edge banner promotions when using Bing or Edge to search for a rival browser. The EEA build shows that a less coercive experience is technically achievable. Outside the EEA, the same levers remain largely in place.
The report doesn’t claim that every individual message is deceptive. Microsoft can fairly point out that Edge runs on Chromium, that it integrates with Windows, and that it offers specific features. The argument instead is cumulative: an OS vendor controlling both the browser and the surface where users download competitors can tilt the field in ways that a standalone browser maker can’t. Repeated defaults, custom presented comparisons, and backup behavior add up to a structural advantage.
Then there’s the AI layer. Copilot, according to Mozilla, can open links in Edge regardless of the default setting. Microsoft’s developer documentation confirms the microsoft-edge: URI scheme exists, and that it will always launch Edge. The question is whether Copilot uses that scheme for links that could and should respect the user’s default. The report doesn’t provide a definitive count, but the potential for session splitting alone makes this worth flagging in any environment that standardizes on a non-Edge browser.
Mozilla also raises a data-governance flag. Separate consent prompts across Windows and Edge could create a “pipeline” that funnels browsing-related data into Microsoft’s personalization and advertising systems, even when the user primarily uses a different browser. This is presented as a risk arising from consent design rather than proof of a specific data transfer in every configuration, but for organizations subject to strict data-handling rules, it’s another reason to audit telemetry and Microsoft account settings alongside browser policy.
What to Do Right Now: Protecting Your Browser Preference
If you’re moving to Windows 11 in the coming weeks or months, here are concrete steps to keep your default browser where you want it.
For home users and small businesses:
1. Check immediately after restore. After using Windows Backup, open Settings > Apps > Default Apps and verify that your preferred browser is listed under “Web browser.” If it isn’t, click the current entry and select your browser.
2. Install your browser before restoring, if possible. Some reports suggest that having the non-Edge browser already present on the new PC before the restore may help. At minimum, install it immediately after the first sign-in.
3. Use a separate backup for browser data. Don’t rely solely on Windows Backup to migrate your bookmarks, passwords, and extensions. Use your browser’s built-in sync (Firefox Sync, Chrome Sync) or a dedicated backup tool.
4. Manually set associations for key protocol types. In Default Apps, scroll to “Choose defaults by link type” and confirm that HTTP, HTTPS, HTML, and PDF all point to your preferred browser.
For IT administrators:
1. Include browser defaults in your migration playbook. Whether you’re using USMT, Intune, ConfigMgr, or a third-party migration tool, explicitly configure the default browser and protocol associations after the user profile lands on Windows 11.
2. Use policy to enforce associations. For Edge, employ DefaultBrowserSettingEnabled and Set default associations configuration CSP. For Chrome or Firefox, deploy their respective ADMX/ADML templates to lock preferences.
3. Test Copilot link behavior. On a representative build, log in with a non-Edge default and trigger link output from Copilot. Note where those links open. If they bypass your default, consider whether users need to be trained to copy/paste links or whether a group policy can apply the microsoft-edge: URI to your compliance controls.
4. Audit telemetry and consent prompts. Review Windows diagnostic data settings and Edge’s own data collection policies. Ensure they align with your organization’s privacy requirements, particularly if users handle sensitive data in a non-Edge browser.
For users anywhere outside the EEA:
Recognize that many of the DMA-mandated mitigations are not active in your region. You’ll encounter more Edge-promoting touchpoints during initial setup, when downloading a rival browser, and during updates. None of them prevent you from installing and using another browser permanently, but the friction is real.
What Microsoft Should Address — and What Happens Next
Microsoft has not yet responded publicly to the Over the Edge 2.0 report. The immediate test is whether the company clarifies Windows Backup’s behavior regarding third-party defaults. A simple statement confirming that this is under investigation, or a KB article explaining how to preserve defaults, would go a long way.
The bigger question is whether the EEA’s browser-choice safeguards will ever be extended globally. Mozilla’s report effectively argues that they should be, and that the technical work is already done. Microsoft has long maintained that its practices are lawful and that users have free choice. The documented unevenness between regions — where a backup restores defaults in one place but not another — makes that assertion harder to defend without a clear explanation.
Regulatory attention could follow. The report is being distributed to competition authorities, according to Mozilla, and the U.S. Department of Justice recently concluded its antitrust case against Google with remedies that touch on default agreements. Whether similar scrutiny lands on Microsoft’s browser promotion inside Windows is an open watch item.
For now, the most actionable insight from the report is also the simplest: a browser default you set today may not survive a Windows Backup migration tomorrow. Check it, plan for it, and don’t assume.”, the migration will respect your choices.