The High-Speed PCI Serial Port is a device driver associated with a PCI serial port on a computer's motherboard or expansion card. This port is typically used to enable communication with serial devices such as modems, barcode scanners, and other legacy hardware. It might be listed in Device Manager under Ports (COM & LPT) or Other Devices if Windows doesn't recognize the hardware properly.

If you're seeing a High-Speed PCI Serial Port under Unknown Devices or with an exclamation mark in Device Manager, it usually means that the appropriate driver for the PCI card or motherboard's serial port hasn't been installed or is outdated. Here's how you can install the correct driver: