Compare two For Each lists in vb.net - vb.net

Question

I have a small problem.
I have two for each routines. One gives me all foldernames in the current folder. The other gives me all window names opened. Both are saving the results in a String. One with newlines, the other with ~, so I can loop through both and get all the items one by one.
This is the part:
Dim Folders As String
For Each Dir As String In System.IO.Directory.GetDirectories(My.Computer.FileSystem.CurrentDirectory & "\Data\")
Dim dirInfo As New System.IO.DirectoryInfo(Dir)
Folders = Folders & dirInfo.Name & "~"
Next
Dim FolderList() As String = Folders.Split("~")
Dim p As Process
Dim Windows As String
For Each p In Process.GetProcesses
Windows = Windows & vbNewLine & p.MainWindowTitle.ToString
Next
Windows = LineTrim(Windows)
This works. But now, I want to compare them.
I only want to get the Folders, where a window exists, which contains the foldername.
For example, I have 3 folders: Test1,Test2,Test3.
I have one Window opened: "Test1 - Window"
Now I only want to get "Test1" as Result once.
I got it working so far, but I get "Test1" 3 times, because there are 3 folders. Because I am creating new Windows by this info, my function spams new windows..
This is the whole function:
Dim Folders As String
For Each Dir As String In System.IO.Directory.GetDirectories(My.Computer.FileSystem.CurrentDirectory & "\Data\")
Dim dirInfo As New System.IO.DirectoryInfo(Dir)
Folders = Folders & dirInfo.Name & "~"
Next
Dim str As String() = Folders.Split("~")
For Each Folder As String In str
If (My.Computer.FileSystem.FileExists(My.Computer.FileSystem.CurrentDirectory & "\Data\" & Folder & "\" & "Status.txt")) Then
Dim StartTime As String = Inireader.WertLesen("Settings", "StartTime", My.Computer.FileSystem.CurrentDirectory & "\Data\" & Folder & "\Time.ini")
Dim StopTime As String = Inireader.WertLesen("Settings", "StopTime", My.Computer.FileSystem.CurrentDirectory & "\Data\" & Folder & "\Time.ini")
If (IsInTime(StartTime, StopTime) = True) Then
Dim p As Process
Dim Windows As String
For Each p In Process.GetProcesses
Windows = Windows & vbNewLine & p.MainWindowTitle.ToString
Next
Windows = LineTrim(Windows)
Dim Ar() As String = Split(Windows, Environment.NewLine)
For Each Window As String In Ar
If sX.ToString.Contains(Window & " - python " & My.Computer.FileSystem.CurrentDirectory & "\Data\" & Window& "\" & Window & ".py") Then ''''The Spam cause line
Else
Dim Path = My.Computer.FileSystem.CurrentDirectory & "\Data\" & Folder & "\" & Folder & ".py"
Dim startInfo As New ProcessStartInfo
startInfo.FileName = "cmd.exe"
startInfo.Arguments = "/k " & "title " & Folder & " & python " & Path
startInfo.WorkingDirectory = My.Computer.FileSystem.CurrentDirectory & "\Data\" & Folder & "\"
Process.Start(startInfo)
End If
Next
End If
End If
Next
I can´t shorten it very much..
Could you help me out?
Thank you :)
Best regards!