"Guitar Hero III: Legends of Rock" is the PC version of the "Guitar Hero" music and rhythm game. In this game, you play songs by pressing buttons that correspond to coloured guitar fret cues on the screen. Though the game comes with a guitar controller, you can also play it with just the keyboard. If you don't like the way the controls are set up, you can also reconfigure the keyboard settings to play the way that works best for you.
Launch the "Guitar Hero III: Legends of Rock" game on your computer, and select the song you want to play.
Press the "A," "S," "D," "F" and "Caps Lock" buttons on your keyboard to play the frets corresponding with the game's guitar.
Press the left mouse button to strum up, the right mouse button to strum down and the mouse wheel button to tilt the guitar.
Launch the "Options" menu in the game, choose "Controller," then "Configure Keyboard" to open the game configuration. Here you can assign different buttons to control the game and customise it to your liking.