Form don't wait for thread finish and hangs my app - vb.net

Question

This is my app, you can see 3 buttons, start button enabled, pause disabled and stop disabled.
The problem is I have a separated thread in my form to make a "process" (and to print the information in the black richtextbox), and my intention is to can pause it or stop it, but when I launch the thread, the pause button and stop button turns Enabled to disabled in a second.
I can tell the form to wait after launching the thread with a _WaitHandle_FirstThreadDone.WaitOne() and then i can see enabled the pause and the stop buttons, but then the problem is my app hangs until the "process" is done.. so I can't push any button.
Please, I need help to make this...
The important part of my form:
Public Class Form1
#Region "Append text function"
' Append Text
Public Sub AppendText(box As RichTextBox, color As Color, text As String)
Control.CheckForIllegalCrossThreadCalls = False
Dim start As Integer = box.TextLength
box.AppendText(text)
Dim [end] As Integer = box.TextLength
' Textbox may transform chars, so (end-start) != text.Length
box.[Select](start, [end] - start)
If True Then
box.SelectionColor = color
' could set box.SelectionBackColor, box.SelectionFont too.
End If
box.SelectionLength = 0
' clear
End Sub
#End Region
#Region "Thread"
Public _WaitHandle_FirstThreadDone As New System.Threading.AutoResetEvent(False)
Public Sub ThreadProc(ByVal aDir As DirectoryInfo)
Dim aFile As FileInfo
For Each aFile In aDir.GetFiles()
If accepted_extensions.ToLower.Contains(aFile.Extension.ToLower) Then
' print output
AppendText(consolebox, Color.Yellow, "Processing: ")
AppendText(consolebox, Color.White, aFile.ToString() + vbNewLine)
consolebox.ScrollToCaret()
processedfiles += 1
totalfiles_label.Text = "Processed " + processedfiles.ToString() + " of " + totalfiles.ToString() + " total video files"
' MEDIAINFO: (ac3, dts, wav and multitrack)
If ac3 = True Or dts = True Or wav = True Or multitrack = True Then
MI.Open(aFile.FullName)
Dim Pos As Integer = 0
To_Display = Nothing
While Pos < MI.Count_Get(StreamKind.Audio)
' AC-3
If ac3 = True Then
If MI.Get_(StreamKind.Audio, Pos, "Format").ToString() = "AC-3" Then
results_box.AppendText("AC3 Track: " + aFile.FullName.ToString() + vbNewLine)
results_box.SelectionStart = results_box.Text.Length
results_box.ScrollToCaret()
problems += 1
problems_label.Text = problems.ToString() + " problems found"
End If
End If
System.Math.Max(System.Threading.Interlocked.Increment(Pos), Pos - 1)
End While
End If
End If
Next
_WaitHandle_FirstThreadDone.Set()
End Sub
#End Region
#Region "Organize function"
Public Sub MediaInfo(Directory)
Dim MyDirectory As DirectoryInfo
MyDirectory = New DirectoryInfo(NameOfDirectory)
MediaInfoWorkWithDirectory(MyDirectory)
End Sub
Public Sub MediaInfoWorkWithDirectory(ByVal aDir As DirectoryInfo)
Dim nextDir As DirectoryInfo
Dim t As New Threading.Thread(AddressOf ThreadProc)
t.Start(aDir)
'
For Each nextDir In aDir.GetDirectories
If playlist = True Then
Using writer As StreamWriter = New StreamWriter(aDir.FullName & "\" & nextDir.Name & "\" & nextDir.Name & ".m3u", False, System.Text.Encoding.UTF8)
'overwrite existing playlist
End Using
End If
MediaInfoWorkWithDirectory(nextDir)
Next
End Sub
#End Region
#Region "Action buttons"
' start button
Public Sub Button2_Click(sender As Object, e As EventArgs) Handles start_button.Click
consolebox.Clear()
' pause / cancel button ON
start_button.Enabled = False
pause_button.Enabled = True
cancel_button.Enabled = True
' Organization process
NameOfDirectory = userSelectedFolderPath
MediaInfo(NameOfDirectory)
' _WaitHandle_FirstThreadDone.WaitOne()
consolebox.AppendText(vbNewLine + "[+] Organization finalized!" + vbNewLine)
consolebox.Refresh()
consolebox.SelectionStart = consolebox.Text.Length
consolebox.ScrollToCaret()
' pause / cancel button OFF
start_button.Enabled = True
pause_button.Enabled = False
cancel_button.Enabled = False
End Sub
#End Region
Private Sub pause_button_Click(sender As Object, e As EventArgs) Handles pause_button.Click
paused = True
End Sub
End Class

Answer 1

The reason the app hangs is the program is blasting through data sequentially. You should add an if statement inside the part that is looping to check for the pause condition in between processing. Its not a good idea to put the on/off controls inside the subroutine like you have because it can only enable the buttons after everything has completed.
I.E to stop the process
For i to 10 Do
If checkbox1.checked = True then Exit Sub 'check for stop condition
'process videos
Loop
To pause it you could implement a stop but make it remember where to start when resumed.
Also why do you have faces of death? That stuff kills braincells.