This is one of the dirtiest desktop systems I've ever worked on. It was surprising the system was still running with how much dirt was inside this system! As part of our full service, the system was cleaned up inside and out. This did take quite some time, but the customer was not charged for the added service.
A computer with this much dust and dirt inside can experience overheating and even component failure. If you bring your system in for service it is always thoroughly cleaned. Doing so will add to the life of your system.