COM Ports...Need Help...

But it is very common for applications (ActiveSync, HotSynch, IrMon) to bascially grab onto the port and not let go. Normally this is bacause the program has loaded some sort of monitoring component or process which does not get unloaded when the program exits.

Similarly, some OS components, such as the Windows Infrared Monitor, will effectively take over a serial port, and other applications cannot use the port until the monitor capability is disabled.

Even worse are programs that make USB ports appear as serial ports (such as those used for cell phone connection). These programs can sometimes create a virtual COM port that conflicts with physical COM port.

And there are also weird issues like if the PC personal firewall application thinks the serial port is being used as a dial-up network connection.

I guess this all explains why USB was invented.....