Instructions
Download Evantal's "Dual Wielding" mod from The Elder Scrolls Nexus. To access the download link, first click on the "Files (1)" tab immediately above the mod description.
Install an unzipping program if you don't already have one. Free options include "7-Zip," "jZip" and "WinRar."
Unzip the mod directly into your "Oblivion\Data" folder. By default, the game installs to "Program Files\Bethesda Software\Oblivion."
Start "Oblivion," but before pressing "Play," press "Data Files." Check the box next to Evantal's "Dual Wielding."
Load a saved game or start a new game. Travel to the Imperial City, located in the center of Cryodill.
Visit "A Fighting Chance." It's located in the marketplace, across from the warehouse. Speak with the shopkeeper to purchase the dual-wielding swords.