This can occur on Windows-based PC's if the iLok has been misidentified by the New Hardware Wizard. Check the Device Manager for unusual items (often listed in the "Other" category, but can also be misidentified as random USB devices such as CD Recorders and Hard Drives). If this has occurred, delete the item from the Device Manager and reboot the computer. If the iLok software has already been installed it should find it properly.