What’s the safest way to clean dust from a gaming PC?

You don’t need to remove every fan for normal maintenance. Disconnecting the computer from power and grounding yourself against the case before handling components is enough for most cleaning jobs. If you remove the graphics card or other parts, place them on a clean, non-carpeted surface and reinstall them only after all moisture and loose dust are gone.

A soft, dry paintbrush works well for loosening stubborn dust while you use air to move it away. Keep the brush gentle and avoid dragging it across exposed circuit boards. I’d use a blower rather than putting a household vacuum directly against the components, since vacuums can create static and their nozzles can bump parts.

Take the PC somewhere like a garage or patio, shut it down, switch off and unplug the power supply, then hold the case power button briefly. Remove the side panels and filters. Wash only the removable filters, and let them become completely dry before reinstalling them. Use an electric blower without letting the nozzle touch anything, and hold each fan still while blowing through it so it doesn’t spin excessively. Blow through the heatsink and graphics card from different angles, but avoid opening the power supply or blasting directly into its fan. A yearly cleaning is usually plenty unless the PC is on the floor or you have pets.

The main practical precaution is stopping the fans with a finger or plastic tool while you clean them. Spinning a fan very fast can stress its bearings and may generate a small voltage, so there’s no real benefit to letting it free-spin. Keep the blower a short distance away, use short bursts, and don’t try to force dust deeper into tight gaps.