Do a clean (re-)install: * Download a fresh Firefox copy and save the file to the desktop. * http://www.mozilla.com/firefox/all-beta.html * Remove the Firefox program folder before installing that copy of the Firefox installer. * Don't remove personal data if you uninstall the current version. * It is important to delete the Firefox program folder to remove all the files and make sure that there are no problems with files that were leftover after uninstalling. ---- Create a new profile exclusively for the Firefox 4 version and create a desktop shortcut with -P "profile" appended to the target to launch that profile. * http://kb.mozillazine.org/Testing_pre-release_versions * http://kb.mozillazine.org/Creating_a_new_Firefox_profile_on_Windows * http://kb.mozillazine.org/Shortcut_to_a_specific_profile * http://kb.mozillazine.org/Using_multiple_profiles_-_Firefox

Thanks for the help. Now for the next step. With the new install as with the old, cannot access gmail. The page opens but hangs then hangs firefox. Tried www.google.com and it also hangs. Thoughts?