Justin Cooper is an aide to former President Bill Clinton, and he is the administrator for the private server located in the Chappaqua, New York, house where Bill and his wife Hillary live. Cooper will later be interviewed by the FBI, and he will say that the decision is made to replace the server because the current server (being run on an Apple OS X computer) is antiquated and people using it are having email troubles.
At the recommendation of Hillary Clinton’s longtime aide Huma Abedin, Cooper contacts Bryan Pagliano, who worked on Clinton’s 2008 presidential campaign as an information technology specialist, to build a new server system and to assist Cooper with administrating it. Pagliano was getting rid of the computer equipment from Clinton’s presidential campaign, so it is decided to use some of this equipment for the new server at the Chappaqua house.
According to a later FBI interview, Hillary Clinton “told the FBI that at some point she became aware there was a server in the basement of her Chappaqua residence. However, she was unaware of the transition from the Apple server managed by Cooper to another server built by Pagliano and therefore, was not involved in the transition decision.”
Between the fall of 2008 and January 2009, Pagliano gets computer equipment from Clinton’s former presidential campaign headquarters, and also works with Cooper to buy additional necessary equipment.
Clinton becomes secretary of state on January 20, 2009, and begins using a clintonemail.com email address around that time, which is hosted on the old Apple server. The new server won’t be operational until March 2009. (Federal Bureau of Investigation, 9/2/2016)