When you try to install Symantec Mail Security for Microsoft Exchange you receive an error stating, Error 1606: Could Not Access Network Location.
This issue may occur if there is an incorrect setting in one of the following registry subkeys:
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\User Shell Folders
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Explorer\User Shell Folders
To fix this problem automatically, download the Fix it tool. Click Run in the File Download dialog box, and then follow the steps in the Fix it wizard. After the wizard completes, reboot the machine.
Link to download the "Fix it" Tool.
Important : This method contains steps that tell you how to modify the registry. However, serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these steps carefully. For added protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs.