The 3Com Gigabit LOM (3C940) is an onboard Ethernet controller that provides a wired network connection on compatible motherboards. Its driver allows Windows to recognize the controller and communicate with it, enabling access to local network resources and the internet.

Key Features

• Wired Ethernet connectivity: Enables the 3C940 controller to send and receive data over an Ethernet connection.
• Gigabit link capability: Supports the controller’s Gigabit Ethernet functionality when used with compatible network equipment and suitable cabling. Actual transfer speeds depend on the entire connection.
• Windows device integration: Allows the adapter to appear in Device Manager, where you can check its status, review driver information, and troubleshoot connection problems.
• Network configuration access: Makes supported adapter settings available through Windows networking tools; the options shown depend on the driver version.

How to Install

1. Confirm the hardware. Open Device Manager and locate the Ethernet controller under Network adapters or Other devices. Check its properties and hardware IDs to confirm that the driver package matches the 3Com Gigabit LOM (3C940).

1. Check Windows compatibility. Before downloading, verify that the package explicitly supports your Windows version and system architecture. For Windows 11, 10, 8, or 7, do not assume compatibility based on the device name alone: this is legacy hardware, and suitable drivers may not be available for every version.

1. Prepare the download. Save the matching driver package and extract it if necessary. If the computer has no working network connection, download it on another device and transfer it using a USB drive.

1. Install the driver. Run the included installer, if provided. Alternatively, right-click the controller in Device Manager, select Update driver, and choose the option to browse your computer for drivers. Point Windows to the extracted folder.

1. Restart and test. Restart if prompted, connect an Ethernet cable, and check the adapter’s status in Device Manager. If installation fails or Windows reports an incompatibility, seek a verified compatible package rather than forcing an unsupported driver.

Common Issues and Fixes

• Install fails or is blocked: The 3C940 driver may be unsigned or incompatible with newer Windows. Install the correct 32-bit/64-bit package in compatibility mode, or temporarily disable driver signature enforcement during setup.
• Device not detected: Confirm the onboard 3Com LAN is enabled in BIOS, then check Device Manager for unknown/disabled network devices. Reseat add-in cards if applicable and scan for hardware changes.
• Version conflicts: Remove any existing 3Com or generic NIC driver in Device Manager, delete ghost network devices, reboot, then install the 3C940 package matching your Windows version.