Thirdly, anti-dust is the last one. In the air there are thousands invisible dust. Some of them will be attaching on the screen or the inside part through the outlet. It's evitable. But too much dust will block the fluency of the power and the performance. It's demanded to clean the dust regularly by hand. In the store, there are many special sets to clean and maintain laptop. You can choose one according to your own interest. Like dell PA-10 AC Adapter and DC359A 402018-001 AC Adapter, they can be cleaned by a soft cloth.