I cannot find any driver claiming the name 'COM2', the device manager does not show this name is occupied. Only COM4 is used, connected to some internal device.
Indeed, if I use 'COM7'  or so everything goes well.
And when I use 'COM1' (which is not a port on this PC) the virtual COM1 gets installed, however the problem then is 'This device is not working properly because Windows cannot load the drivers required for this device. (Code 31)'.

I have setup a virtual null modem COM2-COM8. Configured and plugged in. However, the COM2 does not appear under its "COM2" name. "COM8" does. Device manager shows "Virtual Null Modem x86 Device" and "Virtual Null Modem x86 Device (COM8)". please note, the first item does NOT show COM2. Properties however show 'Location 2', device instance ID is VSBUSDEV\VIRTUALNULLMODEM\1&36444BD7&1&02
So it seems being set for COM2, however the port name COM2 cannot be found from the application. Port name COM8 can be found.
Please advice how to activate the name COM2