Dalvan

Faz um teste usando a função

uses Registry

procedure DefineIEVersao(Versao:Integer=11000);
const
  REG_KEY = 'Software\Microsoft\Internet Explorer\Main\FeatureControl\FEATURE_BROWSER_EMULATION';
var
  Reg: TRegistry;
  AppName: String;
begin
  AppName := ExtractFileName(Application.ExeName);
  //Versao := 11000;
  Reg:=nil;
  try
    Reg := TRegistry.Create();
    Reg.RootKey := HKEY_CURRENT_USER;
    if Reg.OpenKey(REG_KEY, True) then
    begin
      if Versao = 0 then
        Reg.DeleteValue(AppName)
      else
        Reg.WriteInteger(AppName, Versao);
      Reg.CloseKey;
    end;
  except;
  end;
  if( Assigned( Reg )) then
   FreeAndNil(Reg);
end;

anter de chamar a pagina pelo TWebBrowser

DefineIEVersao(8000);