Instructions
Press "Start" on your keyboard and type "BioWare" into the text field.
Press "Enter" when the folder option appears to open it.
Double-click the "Config" folder, followed by the "BioGame.ini" file.
Locate "m_nMaxInventoryItems" in the list. Change the value to "9999."
Click "File" and "Save" to save your changes. This fully maximizes your in-game inventory space to its limits.