'In a form
'Add a command button to the form
Private Sub Command1_Click()
    'After you click this button, try to move the window
    'You will see that the AsyncThread-function was executed asynchronously
    hThread = CreateThread(ByVal 0&, ByVal 0&, AddressOf AsyncThread, ByVal 0&, ByVal 0&, hThreadID)
    CloseHandle hThread
End Sub
Private Sub Form_Unload(Cancel As Integer)
    'If the thread is still running, close it
    If hThread <> 0 Then TerminateThread hThread, 0
End Sub
'In a module
Declare Sub Sleep Lib "kernel32" (ByVal dwMilliseconds As Long)
Declare Function CreateThread Lib "kernel32" (lpThreadAttributes As Any, ByVal dwStackSize As Long, ByVal lpStartAddress As Long, lpParameter As Any, ByVal dwCreationFlags As Long, lpThreadID As Long) As Long
Declare Function TerminateThread Lib "kernel32" (ByVal hThread As Long, ByVal dwExitCode As Long) As Long
Declare Function CloseHandle Lib "kernel32" (ByVal hObject As Long) As Long
Public hThread As Long, hThreadID As Long
Public Sub AsyncThread()
    'Let this thread sleep for 10 seconds
    Sleep 10000
    hThread = 0
End Sub