Reading and writing files causes "The process cannot access the file because it is being used by another process" error - vba

Question

I'm very new to coding so my code is very basic but I am trying to rewrite a file using an item selected from a list box. The code is a recreation of my full code so it's not as thorough but I want to be able to change the "availability" of a product for a website (In theory because this is not a professional project). When I try to read or write the file an error message comes up saying "The process cannot access the file because it is being used by another process".
Dim FileRewrite As String = "FileRewrite.txt"
Dim ValidateID As Boolean
Dim Read As String
Dim IDR As String
Dim YNR As String
Private Sub TxtBxID_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TxtBxID.TextChanged
If TxtBxID.Text.Length = 2 Then
ValidateID = True
Else
ValidateID = False
End If
End Sub
Private Sub BtnAdd_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BtnAdd.Click
Dim ID As String
Dim YN As String
Dim Writer As New System.IO.StreamWriter(FileRewrite, True)
If ValidateID = True Then
ID = TxtBxID.Text
If CBxYN.Checked = True Then
YN = "YES"
Else
YN = "NO "
End If
Writer.WriteLine(LSet(ID, 3) & LSet(YN, 3))
Writer.Close()
LstBxItems.Items.Clear()
Dim Reader As New System.IO.StreamReader(FileRewrite, True)
Do While Reader.Peek >= 0
LstBxItems.Items.Add(Reader.ReadLine)
Loop
Reader.Close()
Else
MsgBox("Please enter a 2 digit ID")
End If
End Sub
Private Sub BtnChange_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BtnChange.Click
Dim ItemToChange As String
Dim Reader As New System.IO.StreamReader(FileRewrite, True)
ItemToChange = LstBxItems.SelectedItem
IDR = Mid(ItemToChange, 1, 3)
YNR = Mid(ItemToChange, 4, 6)
Do While Reader.Peek >= 0
Read = Reader.ReadLine
Writer()
Loop
Reader.Close()
End Sub
Private Sub Writer()
Dim Writer As New System.IO.StreamWriter(FileRewrite, True)
If Mid(Read, 1, 3) = IDR Then
If YNR = "YES" Then
YNR = "NO "
Else
YNR = "YES"
End If
Writer.WriteLine(LSet(IDR, 3) & LSet(YNR, 3))
Writer.Close()
End If
End Sub
I expect the availability of the product in the file to change from yes to no or no to yes but the reader and writer will not work

Answer 1

You cannot write to the file while looping through the same file to read via Reader.Peek