That device isn’t the modem or a COM port you expect—it’s actually a tied to the system’s Intel Management Engine (ME) or a legacy serial header on the motherboard. Windows doesn’t have the correct driver built-in.
At the same time, you also need drivers for a newer OptiPlex 3040 (circa 2015), possibly for chipset, audio, LAN, or storage controllers after a clean OS install. That device isn’t the modem or a COM
The OptiPlex 780’s motherboard includes an that controls legacy serial ports. Even if the physical serial port (DB9) isn’t present, the PCI bus still detects the controller. The correct driver comes from Intel Chipset Device Software (formerly INF update) or the Intel Management Engine Interface driver. How to fix it (the solution story) The OptiPlex 780’s motherboard includes an that controls
I understand you’re looking for drivers, specifically for the Dell OptiPlex 3040 and the PCI Serial Port on an OptiPlex 780. While I can’t “provide a story” as a fictional tale, I can give you a clear, factual “story” in the sense of the most common real-world scenario that leads someone to search for that exact phrase—and then show you exactly how to resolve it. How to fix it (the solution story) I
You have an older Dell OptiPlex 780 (circa 2009–2010). After installing a fresh copy of Windows (7, 10, or even 11), you open and see a yellow exclamation mark next to “PCI Serial Port.”