You want to have a single client PC to not be running an ESU? I can think of 2 ways you might do it. Which method you use depends on what was in the ESU.
1) If you installed the ESU to the PC as part of an update package, then you can reinstall the full parent package, and any other update packages that you need to take.
2) If that ESU did not contain any business functions, then you might try going to OMW, putting the affected objects in a project, and doing an Advanced Get (Get from the Row Exit, not the hand icon in the middle) for those objects from a path code where the ESU has not yet been installed.
Hope this helps (assuming that my first question stated your intention properly).
