The second step is to select a folder with pictures.
When the user selects a folder all of the picture files in the folder will be displayed in a combo box.
When the user selects one of the pictures from the combo box, that picture will be displayed in the picture box.
Continue with the PictureViewer application.
Double click on the mnuSelectFolder and write the code shown below:
Private Sub mnuSelectFolder_Click(sender As Object, e As EventArgs) Handles mnuSelectFolder.Click
FolderBrowserDialog1.ShowDialog()
If FolderBrowserDialog1.SelectedPath <> "" Then
Dim selectedDir As New System.IO.DirectoryInfo(FolderBrowserDialog1.SelectedPath)
'finds a list of all files in the folder selected
Dim selectedFiles As System.IO.FileInfo() = selectedDir.GetFiles
'information about each file in the selected folder
Dim file As System.IO.FileInfo
cboPictures.Items.Clear() 'get rid of any pictures from a different folder
For Each file In selectedFiles 'file will loop for each file in directory
Dim pic As Boolean = False 'we will set pic to true if file is a picture
Dim filename As String = file.ToString 'make it a string so that we can use string functions
filename = filename.ToLower 'lower changes JPG to jpg so we just check fgor jpg, not both
If filename.EndsWith(".bmp") Then pic = True
If filename.EndsWith(".gif") Then pic = True
If filename.EndsWith(".jpg") Then pic = True
If filename.EndsWith(".png") Then pic = True
If pic Then cboPictures.Items.Add(filename) 'only add the file if it is a picture format
Next
If cboPictures.Items.Count > 0 Then
cboPictures.SelectedIndex = 0
cboPictures.Visible = True
Else
cboPictures.Visible = False
End If
End If
End Sub
Test your program and try selecting a folder that contains pictures. You should see the names of the files, but the pictures don't display.
Save all 
before moving on to the next step.