Tempting though it may be, spraying your screen with the same cleaning fluid that you use to clean the rest of the computer is a fast way to damage your monitor. To clean your monitor safely, turn the monitor off, so that the screen is blank. At this point, you should be able to clearly see the dust on your screen. Wipe away the dust with a microfiber cloth. Follow that with a cleaning wipe designed for monitors. You can find such cloths and wipes at most computer retailers.