I do not know how to let the TWS station display the nasdaq, dow, and S&P indexes, and I use its live help. Customer service said that the retail customer cannot access such information since they are not IB's products.
It's true that IB's system will only display those instruments that you can actually trade. Since you can't trade the Dow itself (unless using options or Spiders), TWS won't display the Dow index (likewise the NAZ and S&P). That's why it is advisable to use a separate quote/charting feed of some kind to augment the TWS platform.
some accounts [I can] can see the tickers DJX and SPX. Just select these tickers with type 'index' to get proxies for S&P500 and Dow. It is better than nothing. Of course, you still need an external chart/quote in my opinion. I do use one on the side. vpineomatrix