Dell Support Website (Official) URL:
https://www.dell.com/support/home/en-us/product-support/product/optiplex-790/drivers
Despite Microsoft ending support for Windows 7, Dell still hosts the legacy drivers. Here is the direct strategy: Dell Support Website (Official) URL: https://www
For Intel chipsets:
For Realtek chipsets:
This article targets Windows 7, but a responsible note: Since Windows 7 is end-of-life (no security patches since January 2020), using it on a networked PC is risky. However, if you must (e.g., legacy medical equipment, industrial controllers, or specialized software): Despite Microsoft ending support for Windows 7, Dell
Alternatively, the OptiPlex 790 runs Windows 10 flawlessly (with SSD and 8GB RAM), and network drivers are included natively. For Linux (Ubuntu, Mint, Debian), both Intel and Realtek chipsets work out-of-the-box with kernel modules e1000e (Intel) and r8168 (Realtek). If Linux is an option, you will never need to search for a driver again. For Intel chipsets:
The best and only recommended source is Dell's official Support Website.
Do not use "driver downloader" tools or third-party sites (e.g., DriverGuide, Softonic, CNET) – they often bundle malware or outdated, incorrect drivers.