You can attempt to recreate deleted Active Directory objects after they have been purged from the Active Directory Deleted Objects container by restoring the object from a prior Active Directory backup.
To recreate purged Active Directory objects
On the navigation bar, click the down arrow next to Restore.
In the View by Resource pane, double-click a backup set that contains the most recent System State backup.
If you want to restore Active Directory objects from a previous backup, select the appropriate backup set.
On the Properties pane, under Settings, click Microsoft Active Directory.
Check Recreate deleted objects that cannot be restored from the Active Directory Deleted Objects container.
Click Run Now to start the restore job or select other restore options from the Properties pane.
Any Active Directory or ADAM/AD LDS object or property that is selected for restore will overwrite existing objects and properties, even if you selected Skip if file exists or Skip if existing file is more recent on the General Restore Job Properties dialog box.
Use the Microsoft Active Directory Users and Computers application to reset the object's user password and re-enable the object's user account.
Recreating purged ADAM/AD LDS objects
About restoring individual Active Directory and ADAM/AD LDS objects