Turn off clean-urls Set to maintenance mode Enable default themes, set to garland (else also causes blank screens like memory issue) Download app code and DB Install just drupal on new server and test Disable clean urls, uninstall drupal, truncate DB Restore app DB Clear caches Restore app code Enable www redirection in .htaccess if required Modify app settings file, set permissions Set permissions on folders default and files Enable clean urls Check update.php, increase memory in PHP.ini to 32/64 if insufficient Remove from maintenance mode