Read First How to Record and View Demos

To RECORD a demo:
Step 1: While in game and Spectating the person you want to record, open your console and type in "record username". There cannot be any spaces in the demo name. This will start the recording.

Step 2: When you have enough recorded, in your console, type "stop".

Step 3: Once the demo is stopped, it will be saved in your steam folder. You don't need this but you may want to know where it is.
- Usually it is located at "C:\Program Files(x86)\Steam\Steamapps\Common\Counter-Strike Source\cstrike"

To VIEW a demo:
Step 1: Disconnect from the game. Then, in your console, type "demoui" and hit enter. You will get the following window...

Step 2: Click the "Load..." button and select the appropriate demo file.
- You may have to browse to your steam folder as stated in "To Record a Demo > Step 3.

Step 3: Once the demo starts, you can watch it.
- To make it a bit easier to see if they are walling, you can use "sv_cheats 1" and "r_drawothermodels 2".
- NOTE: sv_cheats is ONLY for use when viewing a demo. You can NOT use it in game so don't try or the server "might" kick you.

Here's a nice video if you are more of a visual person