The site is known for providing "pre-activated" or modified software. Using a standalone version of Vivaldi

: Trusted sites like Npackd and Uptodown also host historical versions like 5.5.2805.50. Security Warning regarding FaresCD

: Choose the Windows 64-bit (Intel / AMD) version.

If you specifically need version 5.5.2805 (for legacy OS compatibility or testing):

: If you need a "portable" or "unzipped" version (similar to a .zip archive): Open the downloaded .exe installer. Click the Advanced button.

: Vivaldi maintains an official Download Archive for older builds.