// UnregisterServer by Ralf Kaiser patterned on RegisterServer
function UnregisterServer(const ModuleName: string): Boolean;
type
  TCOMFunc = function: HRESULT;
const
  S_OK = $00000000;
var
  Handle: THandle;
  DllUnRegServ: TCOMFunc;
  DllCanUnloadNow: TCOMFunc;
begin
  Handle := LoadDLL(ModuleName);
  try
    DllUnRegServ := GetProcAddress(Handle, 'DllUnregisterServer');
    DllCanUnloadNow := GetProcAddress(Handle, 'DllCanUnloadNow');
    Result := Assigned(DllCanUnloadNow) and (DllCanUnloadNow() = S_OK) and
      Assigned(DllUnRegServ) and (DllUnRegServ() = S_OK);
  finally
    FreeLibrary(Handle);
  end;
end;