If you want to add,modify or delete a system tray icon.Follow the below steps:
STEP:1
Go to run and type REGEDIT
STEP:2
Under MyComputer->Select HKEY_LOCAL_MACHINE
STEP:3
Expand the folder SOFTWARE
Step:4
Select and expand the folder MICROSOFT
Step:5
Select the folder WINDOWS and expand it.
Step:6
Expand CURRENTVERSION
Step:7
Double Click the Run
Step:8
In the right side pane,right click the empty area select New->String Value
Type any user defined name and the right click the created name select modify.The below window will come
In that enter the path of your EXE that you want to display as tray icon and click ok.