Because it was officially made free, several preservation and community sites host the full game installer: A popular source for the Windows version.
A first-person shooter where you play as Ethan Cole, a HAZMAT operative fighting a mutagenic virus and alien conspiracy. I Restored Area 51 (2005) for Windows 10/11 (Free Game!) Area 51 (2005) Full Game Download
The full game can be downloaded legally for free because it was released as a freeware, ad-supported title sponsored by the US Air Force in 2008. Since the original publisher, Midway, no longer exists and the game is not sold on major digital stores like Steam or GOG, it is widely considered "abandonware". Where to Download Area 51 (2005) Because it was officially made free, several preservation
Continues to host the original 1.9GB "US Air Force sponsored" free version. Essential Fixes for Modern Systems Since the original publisher, Midway, no longer exists
This is the latest official patch that removes the "StarForce" DRM, which can cause system crashes on modern OS.