Chapter 4 Authentication : Agent-based FSSO : Troubleshooting FSSO : User status “Not Verified” on the Collector agent : Solution
  
Solution
There are a few things that can cause the Collector agent not to be able to connect to the user's work station. Below is a list of the most common causes:
Most commonly, a host firewall on the user's workstation or a router on the network prevents remote access on ports 139 and/or 445. Try opening the ports on the host firewall.
If the remote registry service is not running on the user's workstation, the Collector agent will not be able to connect to the registry remotely. Make sure the remote registry service is running.
This problem may also be caused by a known MS upgrade issue.
Using Regedit.exe, edit “HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\ Control\SecurePipeServers”, set permissions for winreg and allow Local Service with R and W permissions.