To set a client as an Unmanaged Detector:

1. Open and login to the Symantec Endpoint Protection Manager
2. Select the group in which the client that need to be assigned as an unmanaged detector resides
3. Select the client computer
4. Right click on the client computer and select Enable as Unmanaged Detector

To set notifications when using the "Unmanaged Detector" feature in the SEPM
There are two ways to find out if an unmanaged computer is discovered using the Unmanaged Detector feature.
 

• Configure a notification
  1. Open and login to the Symantec Endpoint Protection Manager
  2. Click on Monitors Tab
  3. Click on Notifications
  4. Click on Notification Conditions
  5. Click on Add
  6. Select Unmanaged computers
  
  Correctly-configured notifications should then write events to the database, send notifiation by mail, or perform any other action configured. These notifications can be acknowledged in the SEPM.
   
• Alternate :
  1. Select the Home tab to view the Dashboard page of the Symantec Endpoint Protection Manager
  2. Click on More Details link on the Security Status alert and check for Unknown Device Failures