Uninstall modem software,remove COM1 from device manager, reboot pc with modem connected, windows should pick it up, then install software whem prompted.I had similar problem and this worked for me.
Hands-on: Samsung Galaxy S8 review
1995-2015: How technology has changed the world in 20 years
Samsung's beautifully designed Galaxy S8 makes for better VR experiences too
47 iPhone camera tips to help you take better photos
Synology invites you to visit them at Insomnia on 26th – 29th August. Book your tickets now and visit Synology.