By default, the Portal Super User account is the site’s System
Account, and the Portal Super Reader account is NT Authority\Local
Service.
Give domain\superuser, Full control in user
policy of the particular site from Central administration. And also for
domain\superreader Full read permission in user policy.
If
your web application is using claims based authentication the users
should be displayed like i:0#.w|domain\superuser and
i:0#w|domain\superreader.
To add the user accounts to the Web application by using Windows PowerShell
Verify that you meet the following minimum requirements: See Add-SPShellAdmin.
Copy the following code and paste it into a text editor, such as Notepad:
$wa = Get-SPWebApplication -Identity "http://<server>/"
$wa.Properties["portalsuperuseraccount"] = "i:0#.w|domain\superuser"
$wa.Properties["portalsuperreaderaccount"] = "i:0#w|domain\superreader"
$wa.Update()
Save the file, naming it SetUsers.ps1. Close the text editor.
On
the Start menu,Open SharePoint 2010 Management Shell. Change to the
directory where you saved the file.At the Windows PowerShell command
prompt, type the following command: ./SetUsers.ps1
After you've run these PowerShell cmdlets perform an IISRESET to finish it off.