: WeiDU installers (the standard for IE mods) require a specific hierarchy within your game directory to function.
: Do not install mods into the Documents/Baldur's Gate - Enhanced Edition folder; this is only for save games and portraits. Baldur's Gate Enhanced Edition 7z
: Find where the game is installed (e.g., C:\Program Files (x86)\Steam\steamapps\common\Baldur's Gate Enhanced Edition ). You should see the CHITIN.KEY file in this directory. : WeiDU installers (the standard for IE mods)
Windows. The Slithering Menace mod for Windows is distributed as an extractable compressed archive and includes a WeiDU installer. Baldur's Gate Enhanced Edition 7z
: Right-click your .7z mod file and select "Extract here" or drag the contents directly into your game folder.