Instead of telling people to type in the process name without .exe, you could add something like
If textBox1.Text.EndsWith(".exe", StringComparison.OrdinalIgnoreCase) Then
textBox1.Text = textBox1.Text.Substring(0, (textBox1.Text.Length - 4))
End If
That way it wont matter if they type .exe. Just makes it alittle easier.