Thanks for the welcome! I have Firefox set as the default on every system here and CCleaner still tries to launch IE. To make sure I'm not crazy, I just installed XP SP3 in a virtual machine, installed Firefox 3.5.7, set it as the default browser, downloaded and installed an older version of CCleaner, clicked on the check for updates link and it launched IE 6 even with Firefox set as the default browser. Just to make sure the setting stuck, I rebooted the VM, made sure Firefox was the default, launched CCleaner again, and the update link launched IE 6 again.