These projectors can be used to connect wirelessly which often gives a better quality picture and reduces amount of trailing cables too
Just a case of following these steps and then the laptop should connect to the projector and show what is on the laptop on the projected image from the proejctor
Plug projector into mains power and turn on
Press Windows Key + K on laptop which should make a menu pop up on the right hand side of the laptop screen
It should find the projector so you should then see it in the list, should be called by the room number eg SC4, PE5 etc
Select the correct projector from the list and click to connect to the 'Digital Output (SC4)'
Wait a short while to connect then what is shown on the laptop should now be projected by the projector
Adjust focus at front of projector as required
When finished, turn everything off so the projector is available for the next user