Physically clean your computer's internal components by first turning off the power, removing the case and using compressed air to blow the dust off the parts. Use a cotton swab or coffee filter dipped in isopropyl alcohol to remove tougher dirt and dust from delicate internal computer parts.
Alternatively, use a small vacuum designed for computer cleaning. Clean the dust collected on the external fan intake grates located on the outside of the computer case.
Clean your mouse and keyboard with isopropyl alcohol or baby wipes. Shake the keyboard upside down to dislodge crumbs. Keyboard keys can be removed to gain access to dirt beneath them. Be sure all components are fully dry before plugging them back in.