Special Startup Instructions for the BOINCmgr GUI
When the regular BOINC Manager is started either manually or via the Window Startup folder to always launch every time a user session is started, you can pass a number of instructions or arguments shown in this screen shot.
The most popular would be /s to tell the GUI interface not to open on screen or start minimized to the Start Bar, but rather directly as just an icon in the system tray. Edit the shortcut and building on the default put the application and path in quotation marks and append the relevant instruction which in this case would become e.g. "C:\PROGRAM FILES\BOINC\BOINCmgr.exe" /s
Caveat: It only works if the shortcut is set to open in a normal window. On Max or Min it will do that instead!
The boincargs option does not work. Do not attempt to use this option.
Alternately, you may just start the BOINC core client, without BOINC Manager by simply creating a shortcut containing the following command: "C:\Program Files\BOINC\boinc.exe" --detach effectively running as were BOINC installed as a service. A system tray icon will only be shown during the time BOINC Manager is running (can be started and exited leaving BOINC.exe running in background).