Do not use random torrent sites. Only use the official Fitgirl site (check current reddit r/CrackWatch for legitimate domain updates, as it changes periodically). Search for "Diablo 2 Lord of Destruction 1.13c – Fitgirl Repack."
Unlike traditional repacks, the portable version does write to C:\Program Files or registry. diablo 2 lod 113c portable fitgirl repack
You need the original Diablo II and Lord of Destruction files. Once installed once, you can simply copy the folder C:\Program Files (x86)\Diablo II to any location (like your Desktop or a USB) to make it portable. 2. Downgrading/Upgrading to 1.13c Do not use random torrent sites