In order to keep MXD files from getting too big the default option for Results Management is "2 weeks".
It would be good to have a check box on the Geoprcessing Options to make the choice be default, or to have a setting on the AdvancedArcMapSettings utility to allow setting the default.
When going back to a project done 6 months earlier it is handy to look at the results in order to re-run the processing done on the project. If the default Results Management isn't changed it isn't possible to see which tools were used.
While I understand the problem of bulky MXD files, however, it is a better practice to utilize new MXD's by using templates and layers, rather than continually adding to or copying a single MXD.
A work around is to start with a blank document set the option to "Never Delete" and then save the MXD in:
C:\Users\{user}\AppData\Roaming\ESRI\Desktop10.1\ArcMap\Templates\Template.mxd
Then the option is there to use that template under "My Templates" when creating a new document.
Having the ability to set it as a default would be better.
Emmor
