In a computer room, you would typically find the following items on a desk:
- el teclado (the keyboard)
- la pantalla (the screen)
The other two items, la ventana (the window) and la silla (the chair), are not typically found on a desk. "La silla" can be associated with the desk but is not an item on the desk itself. Therefore, the correct answers are:
- el teclado
- la pantalla