How to Set the Language in a PowerPoint presentation

To change the language of all text in all slides (including the Notes of the slides), use the following macro:

Sub SetLangUK()
'set language to UK for all slides and notes:
Dim scount, j, k, fcount
scount = ActivePresentation.Slides.Count
For j = 1 To scount
fcount = ActivePresentation.Slides(j).Shapes.Count
For k = 1 To fcount 'change all shapes:
If ActivePresentation.Slides(j).Shapes(k).HasTextFrame Then
ActivePresentation.Slides(j).Shapes(k).TextFrame _
.TextRange.LanguageID = msoLanguageIDEnglishUK
End If
Next k
'change notes:
fcount = ActivePresentation.Slides(j).NotesPage.Shapes.Count
For k = 1 To fcount 'change all shapes:
If ActivePresentation.Slides(j).NotesPage.Shapes(k).HasTextFrame Then
ActivePresentation.Slides(j).NotesPage.Shapes(k).TextFrame _
.TextRange.LanguageID = msoLanguageIDEnglishUK
End If
Next k
Next j
End Sub

I got half of this code from Antonín Otáhal and added the part about the NotesPage.