If your language is not available for 2018:
A common installation failure for AutoCAD 2018 occurs when the installer attempts to force-install an outdated .NET Framework language pack over a newer Windows version. If your installation freezes here, Autodesk recommends performing a clean install by grabbing a fresh browser download of the full installer and temporarily disabling antivirus shields. autocad 2018 language pack
A complete language pack for AutoCAD 2018 is approximately depending on the language (Asian languages are larger due to character sets). If your language is not available for 2018: