You can try this extension if you have compatibility issues with other extensions, * https://addons.mozilla.org/en-US/firefox/addon/add-on-compatibility-reporter/ If you still want to downgrade, see here: * http://www.mozilla.com/en-US/firefox/all-older.html (should be updated to include Firefox 4 instead of Firefox 3.x soon, I guess) * http://releases.mozilla.org/pub/mozilla.org/firefox/releases/latest-4.0/win32/en-US/ * [[installing firefox]]

You can check out ( http://www.oldapps.com/firefox.php?old_firefox=112 ).. They seem to have old versions of firefox up[http://www.desirehire.com .].