Не работает прога - "занят" поток - Visual Basic .NET

Public Class Form1
    Public args As String = "1234567890abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        If Not System.IO.File.Exists("C:\Users\Local\AppData\Randoms\RandonCode.db") Then
            System.IO.Directory.CreateDirectory("C:\Users\Local\AppData\Randoms")
            System.IO.File.Create("C:\Users\Local\AppData\Randoms\RandonCode.db")
        End If
    End Sub
 
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Const path As String = "C:\Users\Local\AppData\Randoms\RandonCode.db"
        Dim rndm As Single
        Dim num As Integer = 0
        Label1.Text = ""
        For i = 0 To 3
            For q = 0 To 4
                rndm = Rnd() * args.Length
                Label1.Text += args(Math.Round(rndm - 1))
                rndm = 0
            Next
            Label1.Text += "-"
        Next
        For v = 0 To 4
            rndm = Rnd() * args.Length
            Label1.Text += args(Math.Round(rndm))
            rndm = 0
        Next
        If Not System.IO.File.ReadAllLines(path)(num) = Label1.Text Then
            Clipboard.SetText(Label1.Text)
            System.IO.File.WriteAllText(path, Label1.Text)
        End If
    End Sub
End Class