Cannot open serial port on Windows 2008 R2
Windows 2008 R2 is restricting the use of serial ports by services by requiring that the service account has the "Create a token object" user right assigned. A reboot of the KNM service may be required after assigned the user right.
The serial port is used by KNM when an locally connected GSM modem is connected to the KNM host machine and used to send SMS.
Kaseya Network Monitor, KNM