I'm trying to iterate through a list of users folders in windows in "c:\Users" but exclude the microsoft built-in user folders, the below is the code segment I'm using to accomplish this feat but it's for some reason not working as intended. private readonly List<String> _exclusion = new List<String> { "All Users", "Default", "LocalService", "Public", "Administrator", "Default User", "NetworkService" }; public static bool FoundInArray(List<string> arr, string target) { return arr.Exists(p => p.Trim() == target); } foreach (string d in Directory.GetDirectories(sDir).Where(d => !FoundInArray(