Heres my code. I know its ugly, but it works. There is also code at the end to change the transition properties of all the slides. Btw, i dont have any underscores in my code.
Private Sub CommandButton4_Click()
'File Search and insert
Dim Folder As String
Dim X As String
Dim Num As Integer
Folder = TextBox1.Value
Num = InStrRev(Folder, "\"

Folder = Left(Folder, Num)
Set fs = Application.FileSearch
With fs
.LookIn = Folder
.FileName = "*.jpg"
If .Execute(SortBy:=msoSortByFileName,_ SortOrder:=msoSortOrderAscending) > 0 Then
MsgBox "There were " & .FoundFiles.Count &_
" file(s) found in folder, " & Folder
For i = 1 To .FoundFiles.Count
X = .FoundFiles(i)
ActiveWindow.Selection.SlideRange.Shapes.AddPicture(FileName:=X, LinkToFile:=msoFalse, SaveWithDocument:=msoTrue, Left:=0, Top:=0, Width:=720, Height:=540).Select
ActiveWindow.Selection.ShapeRange.LockAspectRatio =_ msoFalse
ActiveWindow.View.GotoSlide Index:=ActivePresentation.Slides.Add(Index:=1,_ Layout:=ppLayoutBlank).SlideIndex
ActivePresentation.Slides.Range(Array(1)).Select
Next i
Else
MsgBox "There were no files found."
Exit Sub
End If
End With
Dim TmSet As Integer
If IsEmpty(TmCtrl.Value) = True Then
TmSet = TmCtrl.Value
With ActivePresentation.Slides.Range.SlideShowTransition
.EntryEffect = ppEffectNone
.AdvanceOnClick = msoTrue
.AdvanceOnTime = msoTrue
.AdvanceTime = TmSet
.SoundEffect.Type = ppSoundNone
End With
End If
End Sub