When Mozilla Firefox hangs or if it stops responding randomly, a label indicating the browser issue would pop up on the address bar of Firefox and cursor of the mouse would become a spinning wheel if you place it over an open tab. Read on for steps to troubleshoot random hangs in Mozilla Firefox if it happens after an action, such as downloading a large file or while quitting the browser.
If such kinds of unresponsiveness happen on Mozilla Firefox 3 or later periodically, note that the Places database may be corrupt. Places stores bookmarks, keywords, annotations, and browsing history on Firefox browser. Follow the below steps for creating a fresh Places database for storing all that information in browsing sessions afterward. Note that doing this would clear history of visited web pages and bookmarks of a day depending on when you create a new Places database.
Once the browser reboots, it would make a fresh Places database. This would mean that old browsing history on Firefox would be gone, but the browser would import bookmark from the most recent backup file containing that.
If Mozilla Firefox freezes every few seconds even after following the above-mentioned steps, you might have to disable hardware acceleration. This is because with certain graphics driver and card driver set-ups, Firefox tends to hang while hardware acceleration is being enabled. To disable it, click the menu button and select Options. In the new window, deselect Use Recommended Performance Settings option under the Performance tab. Just under that, you have to deselect Use Hardware Acceleration When Available. After that, exit Firefox and see to it if browsing works normally.