Do you see the base64 encoded images that make the flame in the "View Selection Source" via the right-click context menu if you select all the text on the page via Ctrl+A?

Try to reset the browser.startup.homepage_override.mstone pref via the right-click context menu to the default on the about:config page and close and restart Firefox to restore the about:home page to its default.

• http://kb.mozillazine.org/about:config

1. Open the about:config page via the location bar
2. Type in the Filter bar: mstone
3. Right-click the browser.startup.homepage_override.mstone line and select: Reset
4. Close and restart Firefox

Thanks for answering!

The only I see is the default Firefox logo (as if the Olympic cauldron never has existed in my PC). Resetting browser.startup.homepage_override.mstone doesn't work.

Try to delete the webappsstore.sqlite file in the Firefox Profile Folder to remove all cookies and other data stored in DOM storage to make Firefox rebuild the snippets.

• http://kb.mozillazine.org/Profile_folder_-_Firefox

Still not appear.

When I start Firefox I found this error in english (I have FF in spanish) on "error console"

Could not read chrome manifest 'file:///C:/Program%20Files/Mozilla%20Firefox/extensions/%7B972ce4c6-7e08-4474-a285-3208198ce6fd%7D/chrome.manifest'.

Is this realted with my issue?

No, that is a common error in the error console caused by the default theme installation folder that has been moved to the omni.ja archive file.

Try these steps:

1. check that the browser.aboutHomeSnippets.updateUrl has the default value
2. reset browser.startup.homepage_override.mstone to the default.
3. close Firefox
4. delete the chromeappsstore.sqlite file in the Firefox profile folder
5. restart Firefox

Still doesn't work.

A curious note: I installed Firefox portable, and I got the Olympic cauldron, Do you think if it's a good idea to remplace something from the portable version to the installed version?? Or do you suggest reinstalling Firefox??

I finally reinstalled Firefox and I fixed my issue. Seems like Firefox sometimes have troubles like this. Thank you for helping me!