To start TeamDrive Portable minimized, "autostart" needs to be added to the shortcut's target.
This can be done by performing the following.
1. Right-click on the TeamDrive Portable shortcut and select "Properties".
2. In the field "Target" add "autostart" to end of the target. There should also be a Space between autostart and the last quotation mark, i.e. "...\TeamDrive.exe" autostart