To install Left 4 Dead version 1.0.2.7 from a ZIP file, you need to extract the contents and ensure the game executable is correctly registered. Installation Steps Extract the Archive: Right-click the left_4_dead_v1027.zip file. Select Extract All... or use a tool like 7-Zip/WinRAR.
If this is a patch for the Steam version, navigate to your Steam installation folder: C:\Program Files (x86)\Steam\steamapps\common\Left 4 Dead For Standalone/Portable Versions: file left 4 dead v1027zip install
It worked.
Apply → OK.
left4dead.exe