to open the registry editor and add a new entry in HKEY_LOCAL_MACHINE\HARDWARE\DEVICEMAP\SERIALCOMM, but when I close the registry editor and open it again, the entry is gone.
I'm trying to add a registry entry for two serial ports (USB devices). I have made symbolic links to the dosdevices directory. One of my applications is using the COM1 and COM2 ports for normal serial data and it's working fine. I have another application that does not detect the serial ports. I assume that the application get the port info from the registry and that is why I'm trying to modify the registry.
Registry modifications are saved when you close regedit. However, some keys are volatile, and HKEY_LOCAL_MACHINE\HARDWARE\DEVICEMAP\SERIALCOMM is one of them. You couldn't manually add a port there in Windows, either. https://technet.microsoft.com/en-us/lib ... 40908.aspx
The way to add COM ports in Wine is what you've already done, add symlinks.
You didn't mention what Wine version you're using. If it's not 2.0, upgrade. If the problem with the one app is present in 2.0, file a bug.