The Dell OptiPlex 780, released around 2009–2010, uses an Intel Q45 Express chipset. It does not include a built‑in serial (COM) port on the motherboard. A PCI or PCIe serial port card is required. The primary issue is driver support, especially for modern Windows versions (Windows 7, 8.1, 10, and 11) and 64‑bit operating systems.
| Chipset | Recommended OS | Driver Source | |-----------------------|-------------------------------|--------------------------------------------------------------------------------| | MosChip MCS9865 | Windows 7 / 10 (32‑bit only) | Official MosChip site (last updated 2013) – no official 64‑bit Windows 10 driver | | OXPCIe952 (Oxford) | Windows 10/11 64‑bit | Use built‑in serenum.sys / serial.sys after forcing hardware ID in .inf | | FTDI FT4232H (4‑port) | Windows 10/11 64‑bit | FTDI’s official VCP driver – fully signed, works well with OptiPlex 780 | | Startech 1P model | Windows 10/11 64‑bit | Startech provides signed drivers for their cards based on the above chipsets | optiplex 780 pci serial port driver
Here’s a draft review for an OptiPlex 780 PCI serial port driver issue. You can use this as a troubleshooting guide or internal documentation review. Review of Dell OptiPlex 780 – PCI Serial Port Driver Compatibility The Dell OptiPlex 780, released around 2009–2010, uses