(This may take a while, depending on how big the archive is). Click 'Add archive', navigate to the folder where you downloaded the archive, and double click it. A new window called 'omod creator' will appear. OBMM-Installation: Once the mod is downloaded, open OBMM, and click 'Create' in the bottom of the window.if the mod has a esp/esm, be sure to activate it by ticking the checkbox next to it in the plugins tab. If the mod has no esp/esm, it won't appear in the "plugins" tab, but don't worry, it is still installed.
If you are updating a mod you already have, it will prompt you if you want to update or install separately - what to choose here will vary from mod to mod, so be sure to read the installation instructions of each mod! Once it is installed, you can manage the load order in the "Plugins" tab, where you can simply drag-and-drop the esp to change the load order. Then simply double-click the mod in the "Mods" tab of NMM after it has finished downloading your mod.
If you installed your game into your program files folder (which is not recommended), right click the Oblivion.exe either in the Install folder or on your desktop, click properties, navigate to the "Compatibility" tab, and tick the checkbox next to "Run this program as an administrator". Install Oblivion, and for this tutorial we will be using this path 'C:\Games\Bethesda Softworks\Oblivion'.I will take you step-by-step through the process of installing mods for Oblivion, and soon you will be gaming like the rest of us! Note that these instructions are based on Windows 7