How to Change the Input Signal in Counter-Strike
Your computer monitor can only accept a limited range of resolutions, and most full-screen applications have resolution settings that are independent from the Windows configuration. This is especially true for video games such as "Counter-Strike." If your monitor is displaying an input signal error every time you try to start "Counter-Strike," you need to edit the monitor resolution manually in your Steam client.
Determine Your Resolution
Press the "Windows" and "R" keys simultaneously on your keyboard. This opens a "Run" box on the bottom of your screen.
Type "Desk.cpl" into the "Run" box and click the "OK" button. This opens the display information.
Look at the numbers in the "Resolution" drop-down menu. The first number is the width and the second number is the height. Note these two numbers down.
Modify "Counter-Strike" Resolution
Open your Steam client.
Right click "Counter-Strike" in the games list, and then click "Properties."
Click "Set launch options." This will open a dialog box with a text field.
Type "--w width --h height" and then click the "OK" button. Replace "width" and "height" with the numbers you obtained. For example, if your desktop resolution was "1280 x 1024," you would use "-w 1280 --h 1024."
Launch the game.