Check file Attribute
using System; using System.IO; class MainClass { static void Main() { FileInfo file = new FileInfo("data.txt"); Console.WriteLine(file.Attributes.ToString()); if (file.Attributes == FileAttributes.ReadOnly) { Console.WriteLine("File is read-only (faulty test)."); } if ((file.Attributes & FileAttributes.ReadOnly) == FileAttributes.ReadOnly) { Console.WriteLine("File is read-only (correct test)."); } } }