so a friend of mine is a techy out in afghan and he has been given £30,000 to build 25 computers but these pc's are going to be on for between 15 and 20 hours a day and 3 of them need to have 3 screens. he also has a mega problems with dust and sand getting into the current systems he manages and has no idea what he can do to prevent this as all of the systems are fan cooled. i have around 48 hours to get back to him with a few solutions and im completely stuck. any help would be amazing.