Do I need to restart Windows in order for my PC to recognize a DESkey dongle?

Do I need to restart Windows in order for my PC to recognize a DESkey dongle?

No. As long as the DESkey drivers are installed on that PC (the driver installation process does require a restart) then the dongle can be removed or attached freely without any restart required of the operating system. All Tektronix software that requires a dongle will periodically poll for the presence of a dongle and will stop functioning if the dongle is removed and start functioning again as soon as the dongle is re-attached.