<div dir="ltr"><div class="gmail_extra">Marco, it doesn't work that way.</div><div class="gmail_extra"><br></div><div class="gmail_extra">Type helpers simply allow you to extend an existing type with new methods and/or properties. When you declare a type helper you extend all instances of said type given that:</div><div class="gmail_extra"><br></div><div class="gmail_extra">A) You 'use' the unit declaring the type helper in some other unit.</div><div class="gmail_extra">B) No other unit you're using also defines a type helper for that same type. Only one type helper per type allowed.</div><div class="gmail_extra"><br></div><div class="gmail_extra">As to what they are useful for, consider the following:</div><div class="gmail_extra"><br></div><div class="gmail_extra">type</div><div class="gmail_extra">  // IShellLink is define by Microsoft</div><div class="gmail_extra">  IShellLinkHelper = record helper for IShellLink</div><div class="gmail_extra">  public</div><div class="gmail_extra">    procedure Save(const Target, Description, Link: string);</div><div class="gmail_extra">  end;</div><div class="gmail_extra"><br></div><div class="gmail_extra"><div class="gmail_extra">procedure IShellLinkHelper.Save(const Target, Description, Link: string);</div><div class="gmail_extra">var</div><div class="gmail_extra">  P: IPersistsFile;</div><div class="gmail_extra">begin</div><div class="gmail_extra">  SetPath(Target); </div><div class="gmail_extra">  SetDescription(Description);</div><div class="gmail_extra">  if Self is IPersistsFile then</div><div class="gmail_extra">  begin</div><div class="gmail_extra">    P := Self as IPersistsFile;</div><div class="gmail_extra">    P.Save(Link, True);</div><div class="gmail_extra">  end;</div><div class="gmail_extra">end;</div><div><br></div><div>...</div><div><br></div><div>CoCreateInstance(CLSID_ShellLink, nil, CLSCTX_INPROC_SERVER, IShellLink, Link);</div><div><br></div><div>Link.Save('C:\Program Files\Google\chrome.exe', 'Web Browser', C:\Users\me\Desktop\The Internet.lnk')<br></div></div></div>