System.Security.Principal (mscorlib.dll)class
public class WindowsImpersonationContext {
// Public Instance Methods
   public void Undo(  );
// Protected Instance Methods
   protected override void Finalize(  );        
// overrides object

The WindowsImpersonationContext class represents the active Windows user prior to code impersonating another Windows user through a call to the WindowsIdentity.Impersonate( ) method. The WindowsIdentity.Impersonate( ) method returns a WindowsImpersonationContext object. By calling the Undo( ) method of this object, the thread access token reverts to the one contained in the WindowsImpersonationContext object.

Returned By

WindowsIdentity.Impersonate( )

    Part V: API Quick Reference