C#

using System;
using System.IO;

public class test
{
	[STAThread]
	public static void Main()
	{
		test t = new test();
		t.Write();
	}

	private void Write()
	{
		using(StreamWriter sw = new StreamWriter(@"C:\test.txt"))
		{
			sw.WriteLine("Hello Nick");
		}
	}
}

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[DllImport("advapi32.dll", CharSet=CharSet.Unicode, EntryPoint="RegOpenKeyEx")]
static extern long RegOpenKeyEx(
       IntPtr hKey,
       String subKey,
       uint options,
       int sam,
       out IntPtr phkResult);

<br />
private void AddRegNode(TreeNode node, RegistryKey root)<br />
{<br />
RegistryKey rk = root; <br />
String [] subkey = rk.GetSubKeyNames();<br />
if(subkey.Length==0) return;     //if I've no subkeys so I've got only leap<br />
foreach (String s in subkey)<br />
{<br />
String livia = rk.Name + "\\" + s;<br />
RegistryKey temp = Registry.CurrentUser.CreateSubKey(livia);<br />
TreeNode newNode = new TreeNode(s);<br />
this.Tree.SelectedNode.Nodes.Add(newNode);<br />
AddRegNode(newNode, temp);<br />

private void FillNode(TreeView treeView, TreeNode parentNode, RegistryKey key)
{
    int index = key.Name.LastIndexOf("\\");
    string keyname = key.Name;
    if (index > 0)
    {
        keyname = key.Name.Remove(0, index + 1);
    }

    TreeNode node = null;

    if (null == parentNode)
    {
        node = treeView.Nodes.Add(keyname);
    }
    else
    {
        node = parentNode.Nodes.Add(keyname);
    }
    string[] subkeyNames = key.GetSubKeyNames();
    RegistryKey subkey = null;
    foreach (string subkeyName in subkeyNames)
    {
        try
        {
            subkey = key.OpenSubKey(subkeyName);
        }
        catch (SecurityException e)
        {
            // Ignore keys that we don't have security to read them
            continue;
        }

        FillNode(treeView, node, subkey);
        subkey.Close();
    }
}

FillNode(treeView1, null, Microsoft.Win32.Registry.CurrentUser);