Instructions
Download a free copy of official "Counter-Strike 1.6" model fix files.
Click on the "Start" button, and then click on the Start menu's "Computer" shortcut. After the Computer window opens, click on the drive that contains your installation of "Counter-Strike 1.6."
Open the "Program Files" folders, and then open the "Steam" folder inside of it. Open the "Steamapps" folder, and then open your the folder that's marked with your Steam user name. Open the "Counter-Strike" folder, and then open the "Cstrike" folder inside of it.
Drag and drop the downloaded model fix file into the Cstrike folder. Right-click on the zipped model fix file, and then select the "Extract all" option from the context menu that appears. Click "OK" in the extraction menu to unzip the model fix file and complete its installation.