Cleaning a barcode scanner or document scanner requires careful adherence to manufacturer guidelines to avoid damaging delicate optical glass windows or sensitive electronic components. For routine maintenance, first power down or disconnect the device from its power source. Gently wipe down the outer plastic housing using a soft, lint-free microfiber cloth slightly dampened with a mild solution of water and gentle soap or isopropyl alcohol. For the scanning window, use a clean optical lens cloth to remove dust, smudges, and fingerprints without scratching the surface. Never spray liquids directly onto the device openings or use abrasive chemical solvents.