Stick to community forums or well-known modding repositories.
To use TeknoMW3 2.8.0.5b, you typically need an existing installation of the game. teknomw3 2.8 0.5b download
If you are downloading this today, you are likely looking for the "ultimate sandbox" experience of Modern Warfare 3, but be warned: it feels very different from the vanilla game. Stick to community forums or well-known modding repositories