Hi, Rakshit.
SP5 no longer offers options for authentication at the IIS layer. All authentication is handled by the Afaria Server component. This is managed based on your settings in the Server > Configuration \ Security page in the Afaria Administrator. Be sure these values are filled out properly for your environment. To disable authentication now you would need to de-select the "Enable Authentication" checkbox on that page.
Thanks,
Keith Nunn
SAP Active Global Support
SAP Canada