: Skype version 4.0 is over a decade old. Microsoft (the owner of Skype) has long since "retired" these versions, meaning they likely won't connect to modern servers.
💡 : If you are trying to recover old chat logs from a 4.0 installation, you usually only need the main.db file located in the %appdata%\Skype folder, not the old program itself. To help you better, could you tell me: Download skype 405 zip
: Check trusted sites like PortableApps.com for verified, "no-install" versions of modern communication tools. : Skype version 4