Dust is considered bad for the life of computer circuits. It clogs air-filters, insulates electronic components that get hot, and can even cause short-circuits. The proper way to remove dust is by blowing air, because sucking can draw in circuit jumpers. Unfortunately, being a lazy cat, I only clean the inside of my tower when I have cause to open it for another reason. In fact, I’m not even sure how to open the new one, that’s already 6 months old. Spoiler So how often do you clean your valuable machine?