... show a control from code not from resource. I don't know if this could be the problem. I've set up a SysTreeView32 control on this way from RWS CONTROL "", 1007, "SysTreeView32", WS_CHILD | WS_VISIBLE | WS_BORDER, 12, 72, 206, 100 and my code is define dialog oDlg of oWChild resource "nomdepto" ...