In teaching, the issue is students log in and log out the same machine each day with different profiles and log into different machines when they return. Furthermore the students may take their lessons home. In addition, the C drive is not permitted to be used by the students and is infact not accessible (apart from their user folder).
The direction I always give student is to direct all data for projects into each lesson folder .. so for example, lesson001. They start by opening the ArcGISFileHandler.exe and setting the default to x:\gis221\lesson001 and proceed in obtaining the base data for the lesson from arcgis.com and now the data will be directed to the proper folder .. when they work on lesson002 they will be directed to open the ArcGISFileHandler.exe and reset the default folder to the x:\gis221\lesson002 folder. If they want to work on lesson002 at home they take the lesson002 folder (hopefully they set their relative path)
The solution provided to me yesterday is ArcGISFileHandler.exe ... For me and I suspect others, this is pretty important tool to be hidden. I would recommend this should be a menu option in the ArcMAP similar to the setting of the relative path.