On Windows XP SP2 the Windows firewall is predefined and enabled, so this dialog box may appear if you launch or operate software. Confirm that the name of the software appears in the Name field, and that "Yokogawa Electric Corporation" appears in the Issued by field, then click the button to clear the block. Note that once you select to "block" the software you won't be able to launch it again unless you change the Windows firewall settings. To do so, use Windows XP SP2's Help & Support function, and search for "Allow a program to communicate through Windows firewall."