How to enable and disable the CC System Tray Icon.
This can be done a few ways...
1. Altiris Console>Configuration>Solutions Settings>incident Management>Carbon Copy Agent Configuration>select the collection (i.e. All Windows NT/2000/XP) on right pane below the Applies to collection section there is a check box for Display the CC Agent system tray icon. If checked then it will appear if unchecked then it will hide.
2. Locate your CCW32.ini file typically located at C:\Program Files\Altiris\Carbon Copy on the machine where your CC SA is being deployed from. Open the CCW32.ini file and under the Carbon Copy Section edit ShowClientTrayIcon=off or =on, whichever you prefer - off = hide on = show.
3. run command line on the box w/ CC SA from Start>Run>cmd - at the command line back to the root of C and go to the path C:\Program Files\Altiris\Carbon Copy - here run the commands of either client hide or client show - to either hide the icon or display the icon in the system tray...note in order to run the command line properly i.e. to disable the system tray icon - in both the Altiris Console Configuration Policy for that collection would need to be unchecked and policy applied and pulled down on agent side, the CCW32.ini file would have to have the ShowClientTrayIcon set to off - then run the step 3 command line switch above. The reasoning is that if you have the policy enabled on the Altiris Console to display the tray icon - if you ran the command switch to hide the icon - you might be successful at first but once the interval for the agent configuration update ran on the agent side again - it would override the command switch since the policy is currently enabled. Therefore needing to have it disabled on the Altiris console side as well.
As far as windows registry the control for the system tray icon is not done via registry method, rather primarily done via CCW32.ini.