When we open the serial port, sometimes we will prompt "Cannot open the serial port", "The serial port is occupied" and "The serial port resource does not exist".

Solve the problem that the serial port (COM) is occupied.

In fact, all this information reminds us that the serial port you want to use has been occupied by other processes. You can check in the device manager of the computer, COM3 is occupied;

Solve the problem that the serial port (COM) is occupied.

1) When you know what this process is, you can close it in Task Manager;

Solve the problem that the serial port (COM) is occupied.

2) When you don't know what process this serial port is occupied by, you need to handle it from the registry;

Enter regedit in the Start menu Run, and then click OK to open the Registry Editor.

Solve the problem that the serial port (COM) is occupied.

Solve the problem that the serial port (COM) is occupied.

Follow the path in the figure below to find COM.

name

Arbitrator. Then click "right" on "ComDb" on the right and select "Delete". The project to delete the registry is to let win7 rebuild the COM port list so that those ports are not occupied.

Solve the problem that the serial port (COM) is occupied.

Solve the problem that the serial port (COM) is occupied.

Open the device manager again to check that COM3 is no longer occupied;

Solve the problem that the serial port (COM) is occupied.

If you use the serial assistant or other software to open COM3, you will no longer be prompted to open COM3 and other information.

Solve the problem that the serial port (COM) is occupied.

Solve the problem that the serial port (COM) is occupied.