⭐⭐⭐⭐ (4/5) Deducted 1 star only because Dell’s website search can be slow – but the driver itself is excellent.

On the OptiPlex 790, the most common issue is the "Unknown Device" or "Ethernet Controller" appearing in the Device Manager with a yellow exclamation mark. Without this driver, the LAN port on the back of the computer is effectively dead.

Unlike Windows 10 or Windows 11, which typically include generic drivers for most hardware, Windows 7 requires manual installation of specific drivers to recognize network cards.

: Look for the "Intel 825xx Gigabit Platform LAN Network Device" driver. This is the primary driver for the built-in Ethernet port. Driver Pack (CAB File)