How to Install Maps in Counter Strike Sourceby Naomi Bolton
The online first person shooter game "Counter-Strike Source" is often updated with new official maps, but there is also a modding community that offers a selection of free maps. Installing these new maps is usually as simple as extracting the contents of the downloaded archive to the "maps" folder of the game -- but this is not always the case. To ensure that the maps you download are detected correctly by the game it is important to install all the files to the correct folders.
Right-click the compressed map file and select "Extract All." Select a temporary destination folder such as on your desktop and click the checkbox next to "Show extracted files when complete."
Click the "Extract" button and once the extraction is complete the folder with the map files will open. Leave this folder open as you need to copy these files to the correct folders inside your Counter-Strike Source folder.
Right-click the "Steam" icon on your desktop or Start menu and then click "Properties." Click "Open File Location" to open the folder where Steam is installed on your computer.
Double-click the "Steamapps" folder and then double-click the folder with the name that corresponds to your Steam username.
Double-click the "Counter-strike Source" folder. The sub-folders inside this folder are where the various map files must be copied.
Hold down "Ctrl" and click all the files inside the extracted folder that end in the "bsp," "txt" and "nav" extension. Once all these files are highlighted (selected), right-click and select "Copy."
Open the "Maps" folder inside your Counter-Strike Source installation folder and select "Paste."
Copy the files ending in the "ain" extension to the "Graphs" folder.
Copy files ending in the "cache" extension to the "Soundcache" folder.
Copy files ending in the "wav" extension to the "Sound" folder.
Copy files ending in the "vtx," "mdl," "phy" and "vvd" extensions to the "Models" folder.
Copy files ending in the "vmt" or "vtf" extensions to the "Materials" folder.
Close the Counter-Strike Source folder once all the files are copied and delete the temporary folder you created on your desktop. When you launch the game the new map will be visible from the map selection menu.