If I understand correctly, you want to have if one box is checked then other predefined boxes unchecked if checked.
$GUI = GUICreate("Test", 364, 600)
$Box1 = GuiCtrlCreateCheckbox("", 0, 400, 80, 20)
GuiCtrlSetState(-1, $GUI_CHECKED)
$Box2 = GUICtrlCreateCheckbox("", 0, 430, 100, 20)
GUISetState(@SW_SHOW)
While 1
$msg = GuiGetMsg()
Switch $msg
Case $box1
If $Box2 = $GUI_CHECKED Then
GUISetState($Box2, $GUI_UNCHECKED)
Else
GUISetState($Box2, $GUI_CHECKED)
EndIf
Case $Box2
If $Box1 = $GUI_CHECKED Then
GUISetState($Box1, $GUI_UNCHECKED)
Else
GUISetState($Box1, $GUI_CHECKED)
EndIf
EndSwitch
WEnd