[DotNetDevelopment] SerialPort object denied access to serial port on service startup

[James Lamanna]

Hi,
I have a service written in C# that interacts with the serial port.
On the startup of the computer, the service cannot open the serial
port. .Open() returns with an UnauthorizedAccessException.
However, if I restart the service once I log in, everything is fine.
Can someone explain why this might be the case? This seems to only be
a property of the SerialPort object.
I believe using CreateFile() through p/Invoke works...

Thanks.