The reason why you would use a computer cover is to protect your monitor, CPU, keyboard, and printer from computer damaging dust. Using a computer dust cover also will protect your computer from harmful particles that can increase overheating.
Because otherwise dust gets in between the keys.
It will make it unclean
Dust resperator
They protect you eyes from dust.
chemicals and pollution
service the keyboard. the dust inside the key.
Affects the D.O.S Operating system
The main benefit of using a keyboard cover, which is placed on top of a computer keyboard, is that the keyboard is protected from dust, beverage spills and food crumbs. Additionally, keyboard covers are usually washable, so it is easier to keep the typing surface clean.
A great way to keep your keyboard key is to buy a mini usb vacuum. The vacuum plugs into the USB port of a laptop or computer and you simply vacuum the keyboard. This helps to rid crumbs, dust, and any other small objects stuck under your keys. To keep your keyboard looking glossy and clean, you could buy some keyboard wipes. These wipes are made of cloth and wetted with ethyl alcohol. They clean the keyboard of dust, bacteria, and germs.
Key guard is a simple silicon or plastic type mat with glue which you can stick on your keyboard and it will protect your key from water, dust etc. But generally if you don't have one key guard for your key board then it's also alright.
dust cover is protect your computer from dust particles so dust cover is important i also covered my computer to dust cover