CDBuilder builder = new CDBuilder();
builder.UseJoliet = true;
builder.VolumeIdentifier = "A_SAMPLE_DISK";
builder.AddFile(@"Folder\Hello.txt", Encoding.ASCII.GetBytes("Hello World!"));
builder.Build(@"C:\temp\sample.iso");

using (FileStream isoStream = File.Open(@"C:\temp\sample.iso"))
{
  CDReader cd = new CDReader(isoStream, true);
  Stream fileStream = cd.OpenFile(@"Folder\Hello.txt", FileMode.Open);
  // Use fileStream...
}

long diskSize = 30 * 1024 * 1024; //30MB
using (Stream vhdStream = File.Create(@"C:\TEMP\mydisk.vhd"))
{
    Disk disk = Disk.InitializeDynamic(vhdStream, diskSize);
    BiosPartitionTable.Initialize(disk, WellKnownPartitionType.WindowsFat);
    using (FatFileSystem fs = FatFileSystem.FormatPartition(disk, 0, null))
    {
        fs.CreateDirectory(@"TestDir\CHILD");
        // do other things with the file system...
    }
}

using (FileStream fs = File.Create(@"myfloppy.vfd"))
{
    using (FatFileSystem floppy = FatFileSystem.FormatFloppy(fs, FloppyDiskType.HighDensity, "MY FLOPPY  "))
    {
        using (Stream s = floppy.OpenFile("foo.txt", FileMode.Create))
        {
            // Use stream...
        }
    }
}