Enabling and Disabling TaskManager

Please note before we get started that this program must be ran as Administrator.
There are a few Ways that we can do this Check out the MSDN site for the First Method windowsimpersonationcontext. another way would be to add an Application Manifest to your project.

<?xml version="1.0" encoding="utf-8"?>
<asmv1:assembly manifestVersion="1.0" xmlns="urn:schemas-microsoft-com:asm.v1" xmlns:asmv1="urn:schemas-microsoft-com:asm.v1" xmlns:asmv2="urn:schemas-microsoft-com:asm.v2" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
  <assemblyIdentity version="1.0.0.0" name="MyApplication.app"/>
  <trustInfo xmlns="urn:schemas-microsoft-com:asm.v2">
    <security>
      <requestedPrivileges xmlns="urn:schemas-microsoft-com:asm.v3">
        <!-- UAC Manifest Options
            If you want to change the Windows User Account Control level replace the 
            requestedExecutionLevel node with one of the following.

        <requestedExecutionLevel  level="asInvoker" uiAccess="false" />
        <requestedExecutionLevel  level="requireAdministrator" uiAccess="false" />
        <requestedExecutionLevel  level="highestAvailable" uiAccess="false" />

            Specifying requestedExecutionLevel node will disable file and registry virtualization.
            If you want to utilize File and Registry Virtualization for backward 
            compatibility then delete the requestedExecutionLevel node.
        -->
        <requestedExecutionLevel level="requireAdministrator" uiAccess="false" />
      </requestedPrivileges>
    </security>
  </trustInfo>
  
  <compatibility xmlns="urn:schemas-microsoft-com:compatibility.v1">
    <application>
      <!-- A list of all Windows versions that this application is designed to work with. Windows will automatically select the most compatible environment.-->

      <!-- If your application is designed to work with Windows 7, uncomment the following supportedOS node-->
      <!--<supportedOS Id="{35138b9a-5d96-4fbd-8e2d-a2440225f93a}"/>-->
      
    </application>
  </compatibility>
  
  <!-- Enable themes for Windows common controls and dialogs (Windows XP and later) -->
  <!-- <dependency>
    <dependentAssembly>
      <assemblyIdentity
          type="win32"
          name="Microsoft.Windows.Common-Controls"
          version="6.0.0.0"
          processorArchitecture="*"
          publicKeyToken="6595b64144ccf1df"
          language="*"
        />
    </dependentAssembly>
  </dependency>-->

</asmv1:assembly>

Now change the level asInvoker to requireAdministrator as done above on line 24 or just copy and paste this into the app.manifest file. Now that we have this done we will have two protected overrides being the OnLoad and OnClosing Events. OnLoad will Disable the TaskManager and OnClosing will Enable the TaskManager.
To Download the .reg registry scripts to do this you can get those here TaskMgrED Now to see how the code works :)
First we will have an enum that contains our TaskManager Settings and an class That will give us our RegistryKey based on whether the TaskManger is Enabled or Disabled.
you will need to add

using Microsoft.Win32;

public enum TaskManager 
        { 
            Enabled,
            Disabled
        }

As you can see our TaskManager enum is Really straight-forward. Now for the class that holds our RegistryKey

public static class RegEdit
        {
            public static RegistryKey SetKey(TaskManager command)
            {
                RegistryKey mKey;
                string subKey = "Software\\Microsoft\\Windows\\CurrentVersion\\Policies\\System";
                mKey = Registry.CurrentUser.CreateSubKey(subKey);
                switch (command)
                {
                    case TaskManager.Enabled:
                        mKey.SetValue("DisableTaskMgr", 0);
                        break;
                    case TaskManager.Disabled:
                        mKey.SetValue("DisableTaskMgr", 1);
                        break;
                }
                return mKey;
            }
        }

To Call the methods we will use OnLoad to Disable

protected override void OnLoad(EventArgs e)
        {
            RegistryKey regkey = RegEdit.SetKey(TaskManager.Disabled);
            regkey.Close();            
        }

and OnFormClosing To Enable

protected override void OnFormClosing(FormClosingEventArgs e)
        {
            RegistryKey regkey = RegEdit.SetKey(TaskManager.Enabled);
            regkey.Close();            
        }