Question: How dangerous is it to have a physically dirty computer and are there any statistics to support my question?
Answer: The main thing to worry about with a dirty computer is dust on the inside that will cause it to overheat. Dust can act like an insulator keeping the heat in. It can also get into your fans and cause them to fail over time. If you have dirt blocking the case vent holes that that can cause overheating too. If dirt gets into slots like PCI slots then it can affect the connectivity of your components causing problems as well. You should clean your computer once in awhile to keep it running efficiently and to avoid potential problems down the road.