Keep firefox settings when updating
Download folder: Firefox can hang downloading files if the folder where Firefox is attempting to save the download no longer exists or is not accessible.Try resetting the browser.Dir preference in about:config.To open a new window, you must first close the existing Firefox process, or restart your system., Firefox may have stopped responding the last time you closed it.Note that Firefox 3 has a delayed shutdown and will show you this dialog if you try to restart it too soon after exiting.You can also try choosing a new download folder in your Firefox settings: " Tools - Browse".
A hang/freeze is different from a crash, which ends the program.Note: If the Download Manager appears to be stuck scanning for viruses, try closing and re-opening the Downloads window.  Also in some cases security software such as Mc Afee Security Center or Microsoft security essentials has real time scanning that will cause the save file to hang. See Unable to save or download files for more information about file download problems and solutions. Note: If Firefox stops loading websites but does not actually hang, try modifying the max-connections preference in about:config to a lower value, such as 30, which was the previous default before it was increased to 256.If Firefox hangs when accessing page history (e.g., when you click History in the Firefox menu or when you try to clear the browsing history) the file that stores your browsing history may be damaged. For some users, Firefox consumes excessive amounts of memory and may slow down or hang in situations that include being open for long periods of time, after downloading or saving images or other files, or after extensive use with multiple tabs open.     (For other problems loading websites, see Error loading websites).Firefox may become very slow to respond because of badly coded Java Script causing infinite loops on certain websites .