The code you have runs the Insert Picture from file dialogue which I think
will always target screen center. You could use instead

Private Sub CommandButton1_Click()
ActivePresentation.SlideShowWindow.View.Slide.Shapes.AddPicture _
"C:\Documents and Settings\John\My Documents\ff.png", msoFalse, _
msoTrue, 50, 60
DoEvents
End Sub
Obviously change the file path. The 50 and 60 are Top and Left for the
inserted pic

This'll help you insert the picture w/o distorting it, once you know the name
of the file you want to insert:

Insert a picture at the correct size
http://www.pptfaq.com/FAQ00329.htm

You can add code to set the picture's .Left and .Top properties to whatever you
like.

-----------------------------------------
Steve Rindsberg, PPT MVP
PPT FAQ:  www.pptfaq.com
PPTools:  www.pptools.com
================================================

I found your last post

You will need this if you want to browse

Sub Pics()

Dim strPath As String
Dim fd As FileDialog
Set fd = Application.FileDialog(msoFileDialogFilePicker)
With fd
.Filters.Clear
.Filters.Add "Pictures", "*.jpg,*.png" ' more if you want!
If .Show = -1 Then
strPath = .SelectedItems(1)
End If
End With

ActivePresentation.SlideShowWindow.View.Slide.Shapes _
.AddPicture strPath, msoFalse, msoTrue, 50, 60 '50 is Top, 60 is left position

Set fd = Nothing

End Sub

Regards John