Set the Window Option to Overlapped Windows, Go to File/Options/Current Database, under Document Window Options, select Overlapped Windows instead of Tabbed Documents. Adjust the form's property sheet, open the form in Design View and verify the following settings on the format tab Auto Resize: Yes, Auto Center: Yes, Fit to Screen: No, Border Style: Thin or Dialog (Avoid Sizable if you want to lock the dimensions), Min Max Buttons: None or Min Enabled (to prevent manual maximization)

Since .accde files lock the Design View and compile VBA, you can not make design changes directly on the .accde file. You must apply these fixes to your original .accdb source file and then recreate the .accde.

As an alternative approach lock dimensions & position via Form Properties and VBA. Adjust the form's property sheet, open the form in Design View and set Auto Resize: No, Auto Center: No (Set to No so it doesn't override the custom top/left coordinates), Fit to Screen: No, Border Style: Thin or Dialog (Avoid Sizable if you want to lock the dimensions), Min Max Buttons: None or Min Enabled (to prevent manual maximization) and set form dimensions and position on open or on load event like

Private Sub Form_Open(Cancel As Integer)
' DoCmd.MoveSize [Right], [Down], [Width], [Height]
' Right: Distance from the left edge of the screen (X position)
' Down : Distance from the top edge of the screen (Y position)
' Example:
' Left: 1000 Twips (~1.8 cm), Top: 1000 Twips (~1.8 cm) Width: 8000 Twips (~14 cm), Height: 5000 Twips (~9 cm)
  DoCmd.MoveSize 1000, 1000, 8000, 5000
End Sub