Mozilla Bypasses Windows 10 Default App Protection

Mozilla developers have successfully reverse-engineered the mechanism for setting the default browser in Windows 10, bypassing Microsoft’s protection designed to prevent malicious programs from setting themselves as default. As many know, Microsoft provides a simplified one-click process for setting its own browser as default, while other browsers are forced to open the system’s “Settings” menu.

Starting with version 91, Firefox has learned to use the same mechanism that Microsoft implemented exclusively for its own browser. Firefox 91 was released on August 10, but this change was not widely publicized for obvious reasons—mainly to avoid potential conflict with Microsoft. Still, it’s important to highlight this significant technical achievement, as reported by The Verge.

This reverse engineering now allows users to quickly set Firefox as their default browser without having to manually navigate through settings or click through new pop-up menus warning against the change. In the new version, Firefox handles the entire process in the background, without additional prompts.

Microsoft Makes Default App Changes Even Harder in Windows 11

In Windows 11, Microsoft has made it even more difficult to set third-party apps as default. After selecting an alternative browser, Windows 11 prompts users to reconsider and keep Edge as the default.

Mozilla representatives argue that Microsoft’s approach is unfair, which justifies their “hacker” efforts. Since Microsoft hasn’t provided an official, easy way to set a default browser, Mozilla had to find a workaround. Mozilla has been urging Microsoft to simplify the default browser process since an open letter in 2015, but nothing has changed. In fact, Windows 11 makes switching default browsers even harder. This seems to have been the last straw, as Mozilla began implementing these hacks in Firefox shortly after the Windows 11 announcement in June, according to The Verge.

So far, Google, Vivaldi, Opera, and other Chromium-based browsers have not followed Mozilla’s example, and it’s unclear how Microsoft will respond. On one hand, Microsoft is protecting its operating system from malware; on the other, it’s creating an uneven playing field, which understandably frustrates competitors—especially Mozilla, which has been steadily losing browser market share for years.

Firefox’s Market Share and the Future

According to Mozilla’s own statistics, Firefox has lost about 41 million users since 2019—a troubling trend for the only real alternative to the Chromium browser family. Perhaps reverse-engineering Windows 10/11 and ongoing controversies around Google Chrome will help Firefox restore its reputation as the last bastion of user protection and win back its audience.