Step-by-step explanation:
firstly, I'd ask the user of the computer to describe in detail the issues they are having with the computer. I'll ask them when this issue started, how long has it been going on and if they have taken any measures to solve the problem and if so what measure was taken.
Secondly, If I haven't gather enough information to try to solve the issue then I'd have move on to checking if this specific problem has already been encountered in my documentation of problems. If it is then I'd follow the steps of my documentation to solve the problem. If not then I'd have to think about the problem. I'd run a self diagnostic test on the computer to see if i can get a clue to solving the problem.
Thridly, if the diagnostic test doesn't work then I'll have to take a look at external sources to resolve the issue. Then hopefully I'll have an understanding of how to fix the problem.