Does not enable a menustrip item when the folder has files with - vb.net

Question

My form's Load event handler checks if a folder is available (if not, it creates it) and if available checks if there are files with a specific extension. If there's at least one file with that extension, it will enable an option on a MenuStrip (referred to as QuickLoadMenuStripItem).
The problem is when it checks a folder when it's on the user's folder, it does not work, regardless if there is or not. It executes the code normally, but it always gives false. Here's the code:
Public Class BaseForm1
Private Sub BaseForm1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
Dim ImportFolder As String = Environment.GetFolderPath(Environment.SpecialFolder.UserProfile) + "\Immortal Sins\Saves\"
If (Not Directory.Exists(ImportFolder)) Then
Directory.CreateDirectory(ImportFolder)
QuickStartToolStripMenuItem.Enabled = False
Else
Directory.GetFiles(ImportFolder)
For Each tempstring As String In ImportFolder
If tempstring.Contains(".isgsf") Then
QuickStartToolStripMenuItem.Enabled = True
Else
QuickStartToolStripMenuItem.Enabled = False
End If
Next
End If
End Sub
End Class
For reference, it checks on C:\Users\\Immortal Sins\Saves. The files have the .isgsf extension.

Answer 1

You could just do:
Private Sub BaseForm1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
Dim ImportFolder As String = System.IO.Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.UserProfile), "Immortal Sins\Saves\")
If (Not Directory.Exists(ImportFolder)) Then
Directory.CreateDirectory(ImportFolder)
QuickStartToolStripMenuItem.Enabled = False
Else
QuickStartToolStripMenuItem.Enabled = (Directory.GetFiles(ImportFolder, "*.isgsf").Length > 0)
End If
End Sub

Answer 2

You're not storing the file list on ImportFolder when retrieving the content at Directory.GetFiles(ImportFolder)
Also, you're not checking the file extension. You're checking if the file contains a certain string.
Try this instead
Dim ImportFolder As String = Environment.GetFolderPath(Environment.SpecialFolder.UserProfile) + "\Immortal Sins\Saves\"
If (Not Directory.Exists(ImportFolder)) Then
Directory.CreateDirectory(ImportFolder)
QuickStartToolStripMenuItem.Enabled = False
Else
Dim fileEntries As String() = Directory.GetFiles(ImportFolder)
For Each file As String In fileEntries
Dim extension As String = System.IO.Path.GetExtension(file)
If extension = "isgsf" Then
QuickStartToolStripMenuItem.Enabled = True
Exit For 'Once a .isgsf is found the next files should't be checked
Else
QuickStartToolStripMenuItem.Enabled = False
End If
Next
End If