Restore the active window.
Syntax DoCmd.Restore
Assuming the default menus are available, use the window menu to switch between forms/windows.
For Restore to be effective you first have to change the Access option to allow Overlapping Windows.
The form must also be the active, selected object.
DoCmd.SelectObject acForm, "frmName"
DoCmd.Restore
“The blush of dawn may yet restore, Our light and hope and joy once more” ~ Celia Thaxter
Maximize - Enlarge the active window.
Minimize - Minimise a window.