By Inquory Research
Published October 9, 2026. News development: October 7. Sources checked October 9. AI-assisted research and drafting; editorially reviewed. Inquory has not tested these Windows journeys or changed a reader’s device.
Mozilla renewed its criticism of Microsoft's browser-choice practices on October 7 and said it is taking the findings of Over The Edge 2.0 to regulators and policymakers. The Firefox maker says some Windows surfaces continue to send people to Edge after they choose another browser. Those are Mozilla's allegations, rather than a newly announced Windows feature or an adjudicated finding. Mozilla's October 7 statement
The useful reader question is narrower: which preference governs the thing you are opening? A browser chosen for web links, an app associated with a document format and a preference inside a messaging app can be different settings. Identifying the originating surface makes a complaint more precise and a settings check easier to interpret.
What the report supports, and where its evidence stops
The Mozilla-commissioned report was authored by Harry Brignull and Cennydd Bowles, who state that its findings are their own. Its walkthroughs used Windows 10 Home and Windows 11 Home in the US, UK, India and Germany. Canada was not a tested region. The authors warn that updates and partial deployments can change experiences; the research documents design patterns rather than measuring each pattern's consequential impact. Report: authors, method and caveats
One documented example followed a taskbar search after Vivaldi had been set as default. The authors report that the panel's browser-results action opened Edge in their US, UK and India tests, while their German tests opened Vivaldi. Their separate file-association discussion reports PDFs and SVGs remaining assigned to Edge in specified tests after Firefox became the default browser. These are bounded research observations, not proof of today's behaviour on every Canadian PC. Report: printed pages 44–48 and 55–58
The report's extracted cover says May 2026; Mozilla's earlier announcement is dated July 14, and its follow-up October 7. Those are separate dates. We use the dated follow-up as the news hook, without independently adopting its elapsed-time label. Earlier announcement
Separate the three layers
Microsoft's Windows documentation describes assigning applications by file type, link protocol or application under Settings → Apps → Default apps. It provides a route for inspecting individual associations. That configuration documentation supplies context; it does not establish the result of every system-generated link. Microsoft's default-app documentation
| Layer | Reader question | Useful observation |
|---|---|---|
| Default browser | Which browser is selected for ordinary web links? | The installed browser and relevant web-link associations |
| File or protocol association | Which app opens this particular format or link type? | The specific association, such as a PDF document |
| Originating app preference | Does this application have its own link-opening choice? | The app's documented option and the browser it actually opens |
Inquory analysis: a single successful link opening answers only that route. It cannot establish that an OS search panel, a local document and a message link all follow the same preference. Equally, one unexpected destination does not establish that every default was reset.
Outlook and Teams are a separate documented case
Microsoft describes a link-opening preference for Outlook for Windows and the Teams desktop app for Windows. Its support page says this does not replace the Windows default-browser setting and gives app settings for choosing a browser. It names commercial Microsoft 365 and Personal or Family subscribers for Outlook, and work-account users for Teams. Managed environments have separate administrator guidance. Microsoft's Outlook and Teams explanation
That page helps explain why an application preference belongs in the table. It does not independently confirm the report's Search, Widgets or Copilot findings, nor show that the same menus or permissions exist in a particular installed build.
Make an observation that someone else can understand
Consider fictional Priya, who opens a harmless public web address from a message and later opens a local PDF. Her private note records the originating app or surface, document or link type, Windows and app versions, chosen setting and actual destination. She keeps the two observations separate. This is an illustrative reporting method; Inquory has not performed Priya's checks.
Before changing a preference, record its current state. Use the documented control that belongs to the observed route, then check that same route again. On a work or school device, ask the administrator if a control is managed. Avoid registry workarounds, disabling protections or changing a device's jurisdiction to imitate the report's regional tests. A public support question usually needs neutral versions and labels, not email contents, private addresses or browsing history.
What remains unresolved
Mozilla says it discussed the report with Microsoft. This article does not establish a new direct Microsoft response. Microsoft's March 2023 principles are historical context, not a rebuttal to the October statement. Microsoft's 2023 principles
A useful future resolution would pair a specific surface and installed build with a documented routing rule and an observable result. Until then, the report's criticism should retain its attribution and limits. This article makes no finding of unlawful conduct, measured privacy or security harm, Canadian rollout parity or guaranteed outcome from changing a setting.
Research and illustration disclosure
This is source-based news analysis, not a hands-on Windows review. Vendor publications and commissioned research are identified above; neither is presented as independently verified user outcomes. The original illustration is conceptual and carries the visible credit AI-generated editorial illustration · Inquory. It depicts three routing layers, not Microsoft or Mozilla software.