I'm not sure which display setting you're talking about so I'm going to answer with two possibilities.
One set of display settings is within the user profile; since you've only got to do this for one user, the simplest way is to log on as that user, change the setting and log out. That will save the setting to their user profile.
The other possibility is that you're talking about their terminal services display settings, which aren't in their profile. You change this from the RDP file they use to log on. For example, if you're using Remote Desktop Connection then change the display settings by opening Remote Desktop Connection, clicking on the "Options" button, and changing settings on the "Display Tab'. Save these settings and distribute the resulting RDP file to the user.
This was first published in September 2005