Here is the annoying part: Encarta 2005 was built for Windows XP. It will not install or run correctly on modern Windows 11 or macOS without workarounds.
First, a hard truth: Microsoft discontinued Encarta in 2009 and officially shut down its servers. You cannot legally buy a digital download from Microsoft anymore. However, physical CDs/DVDs are considered "abandonware" by many archivists. You can find ISO files on the Internet Archive (archive.org) – search for "Microsoft Encarta 2005 ISO." Since the software is defunct and no longer sold, most communities treat downloading it as preservation, not piracy. microsoft encarta 2005 download