| Port Enumeration |
| EnumPhysical | Refreshes information about physical serial ports (or third-party virtual serial ports) and returns their number. |
| EnumVirtual | Refreshes information about virtual serial ports and returns their number. |
| GetPhysical | Retrieves the name of physical serial port by index. |
| GetVirtual | Retrieves virtual serial port name by index. |
| Creating and Removing Ports |
| CreatePort | Creates virtual serial port with non-standard name. |
| CreatePortOverlapped | Creates virtual serial port over existing COM port. |
| RemovePort | Removes a virtual serial port with non-standard name. |
| Other |
| GetLastError | Returns last error code for the latest operation. |