Question

how to find a file is System file or hidden file ?

for example ‘C:\File.txt’ is system file or not .
also is it hidden or not ?

Answer 1

You could use the GetAttributes method:

var att = File.GetAttributes(@"c:\file.txt");
if ((att & FileAttributes.Hidden) == FileAttributes.Hidden) 
{
    // the file is hidden
}

if ((att & FileAttributes.System) == FileAttributes.System)
{
    // the file is system
}