Downloading the preview and running it on a Windows 8 machine should be enough, but we’ve received reports that some users can’t make the browser work. What’s more,
some of the workstations here at the Softpedia labs could not run the Metro Firefox for Windows 8 at all.
The problem is always the same: it seems to install fine, it even places a shortcut in the Windows 8 Start Screen, but whenever you click its icon, you’re instantly switched to the Start Screen. Instead of the Metro version, the shortcut launches the standard desktop version.
Because we’ve heard that so many people encounter problems when trying to run the Metro Firefox, we’ve created this tutorial to lend you a hand and thus help all Windows 8 fans get a taste of the new browser before its official debut. Mozilla hasn’t said anything about the final version of Firefox for Windows 8, so keep in mind that this is an incomplete, unstable and sometimes very slow build.
Step 1: Download the Nightly build of Metro Firefox and extract all files on the desktop. The package is also available on Softpedia, so click here to get it (keep in mind that it’s version 18.0a1 Nightly that we need).
Step 2: Go over to the extracted files and browse to Firefox\metro\install.
Step 3: Double click “zipbuildsetup” and click “Run” to allow the process to launch. You will see a “Command Prompt” window that will automatically close after a few seconds.
Step 4: The same “install” folder holds a file called “registerbrowser.” Launch it and wait. It will modify the Windows 8 registry, so if you have any app that could block this change, make sure you disable it. A confirmation message should appear when the process is completed.
Step 5: Once again, in the “install” folder you shall find another file called “createshortcut.” This one will add the Firefox Nightly shortcut in the Start Screen and will allow you to launch the browser in Metro mode. Double-click it and wait for a few seconds. Some Windows 8 workstations may need a separate file called “msvcr110.dll,” so in case the file asks you for it, use Google and download it.
in order to run Firefox in Metro mode, you need to set the Nightly build as your default browser. There’s no need to uninstall the stable release of Mozilla Firefox because the Nightly version installs in a different location, so it’s enough to launch it and use the “Set as default” option.