if you are referring to a slow internet connection, this is because the computer is using the internet. You cannot fix this, without buying a new internet connection for each computer. Think of this like a pie-graph. The ful pie is how much internet you can use at once. Each computer will start with 33% of the pie. When you go to download a file on one of the computers, that computers slice will take up a larger percentage of the pie, thus decreasing the others.