Here is a rather detailed guide about every computerlocations. First let's see overall how many computers you have to repair at each floor:
Floor 15 - CCO: 2 (#9, #13)
Floor 2 - Helix Research: 10 (#1, #4, #5, #6, #8, #10, #14, #15, #16, #17)
Floor 1 - Lobby: 5 (#2, #3, #7, #18, #19)
Basement - Servers: 3 (#11, #12, #20)
Computer #1
Second Floor: Server Room, Upper-Left. Rewards players with Inspiration: Al Mualim
Computer #2
Lobby: Server Room, Left Side. Vidic’s New Recruit
Computer #3
Lobby: Upper-Left. Florence goes FUBAR
Computer #4
Second Floor: Near Elevator. Inspiration: Haytham Kenway
Computer #5
Second Floor: Locked Room on Right Side. The Soldiers
Computer #6
Second Floor: Center of Cubicle Farm. The Ankh
Computer #7
Lobby: Just outside of elevator hallway. Inspiration: Daniel Cross
Computer #8
Second Floor: Upper-left Meeting Room. The Leaders
Computer #9
15th Floor: Entrance Area. Sigma Team’s Most Wanted: The Cult
Computer #10
Second Floor: Locked Room on Right Side. The Koh-i-Noor
Computer #11
Basement: Server on Left Side. Sigma Team’s Most Wanted: Cross Training
Computer #12
Basement: Top Side of X Room. Inspiration: Duncan Walpole
Computer #13
15th Floor: Server Room on Upper-Right Side. Inspiration: Baptiste
Computer #14
Second Floor: Locked Room on Left Side. New Orders
Computer #15
Second Floor: Locked Room on Upper-Right. Sigma Team’s Most Wanted: The Dead
Computer #16
Second Floor: Left side of Cubicle Farm. Lindsifarne
Computer #17
Second Floor: Locked Room on Upper-Right. Cairo Debrief
Computer #18
Lobby: Top Side, on Right. The Box
Computer #19
Lobby: Just past elevator hallway. Paris
Computer #20
Basement: Right side of X Room. Sigma Team’s Most Wanted: The Support