How to change/select the type of use (Concurrent or Single) in the ArcGIS Administrator?
This feature can be activated ONLY when your launch 'ArcGIS Administrator' as 'Admin'.
1. Launch 'ArcGIS Administrator' as Admin by right clicking the app. See figure 1.
Fig. 1 - how to launch 'ArcGIS Administrator' as 'Admin'
2. When 'ArcGIS Administrator' is open, click on “Desktop” from the left-side column. Select the right user type from the list - eg. Standard (ArcEditor) concurrent use or Standard (ArcEditor) Single use then click on 'Apply'. See figure 2.
Fig. 2 - select/change the right user type