Can anyone tell me how to work the recording and how to watch it cause i tried recording it and i typed this on the command "demo NAME" and it doesnt do anything. Can anyone also tell me how to make the game into fullscreen i tried it on the option in the game but it is still in 640x540 i think. PLEASE TELL ME

You can't change the resolution of Soldat, it's hard coded at 640*480 pixels. You can either play in fullscreen or windowed mode (can be changed with config.exe).

To record a demo, just press "F8". The text "Rec" will be blinking in the upper right corner of your screen.
If you want to find out how to watch them:
Click this link and see how many people already asked this. or read the manual or download "DDplayer".