Determine if filename is valid without creating file.

If IsValidFilename("Text.txt") Then My.Computer.FileSystem.WriteAllText("Text.txt", "Text to write.", False) Else MsgBox("Invalid filename, please use another.") End If Public Function IsValidFilename(ByVal PathAndFilename As String) As Boolean Dim FileData As FileInfo = Nothing Dim IsValidName As Boolean = Nothing Try FileData = My.Computer.FileSystem.GetFileInfo(PathAndFilename) IsValidName = True Catch ex As Exception IsValidName = False End Try If IsValidName Then If (FileData.Name Like "[!A-z]*") Or (FileData.Name Like "*[;=+#%&]*") Then IsValidName = False End If If FileData.Name.Contains("[") Or FileData.Name.Contains("]") Then IsValidName = False End If End If Return IsValidName End Function