From a recent discussion that I had with Harlan Carvey about the registry, this topic is something that I touched on lightly in Placing the Suspect Behind the Keyboard . I want to expand upon beyond the registry regarding a computer having a personality.
The bullet point
By examining multiple computers (or a single system) for computer usage and/or configuration, the owner of the computer can potentially be identified or tied to the computer.
The longer version
I am sure that each time you buy a new computer (laptop, smartphone, tablet, etc…), you spend the first minutes or hours setting it up just the way you like it. Whether it is changing the desktop background, colors, fonts, sounds, or general configuration, you make it yours. You do this every time. To every system that you have. You make it yours.
The way that anyone sets up their machine reflects their likes, dislikes, wants, needs, priorities, and general flow of system use. Generally, and most always, all the systems of one owner are set up very similarly. This is a simple observation; however, it can be a very important investigative clue when you have a system that has been disavowed by a suspect. Any computer that has been disavowed by a suspect (“That’s not my laptop!”) just might have relevant evidence on it if it does in fact belong to the suspect. But how do you prove it if there is nothing on the computer that directly names your suspect?