Because this is an article, not a how-to-pirate guide, we must mention the legal ways to own the complete series.
If you type "Futurama Complete Series Internet Archive" into a search engine, you are generally led to user-uploaded collections. These are not official releases. Typically, a user (often going by a handle like "Video_Viking" or "SpacePirate3000") will upload a compressed folder.
What does the "Complete Series" usually include?
The files are usually MP4 or MKV formats, ranging from 480p (DVD rip) to 1080p (HDTV rip). The total size is massive—often 30GB to 60GB.
If you have decided to venture into the stacks, follow this guide:
Safety Warning: While Archive.org itself is safe, never download an .exe file or a setup.exe. A "Complete Series" should be a folder of .mp4 or .mkv files. If you see a password-protected ZIP or an executable, run away.
The presence of Futurama on the Internet Archive sits at the center of the copyright vs. preservation debate.