Hi, sorry, i´m not really sure if it is actually the firewall causing this problems. On a machine some applications seem not to function, probably due to restricted rights in some directories. I couldn´t find out which ones, though. Also, trying to execute some DOS commands will fail. The window will close immediately without no action. For example, the command Subst x: f:\files won´t do anything when called from the file manager, while in external DOS it is working. Also CCleaner would fail & some tool for using encrypted runas commands. I looked everywhere in the Comodo prefs, but since the interface is a bit confusing & very crowded, i couldn´t find the possible reason. How can the settings completely be reset in order to retest all functions? I assume that one wrong click can cause effects like this, blocking some important dll or restricting some child function to some program.