One way to stream old Hindi movies is to visit popular streaming video sites such as YouTube and DailyMotion and enter the term "old Hindi movies" in the search box. A list of free old Hindi movies is available for viewing. Alternatively, Spuul.com and Boxtv.com are dedicated to streaming movies.
Spuul.com has a good collection of new as well as old Hindi movies. To access old Hindi movies, go to Spuul's home page. Navigate through the page, and click on Flashback Bollywood. This takes you to the full list of old movies available for streaming. Click on the desired movie. The movie starts playing in the browser window. Even old movies on Spuul are available in good quality, and the user can choose screen resolution of up to 480 pixels, though high-definition is not available for most of the movies.
A similar website is Boxtv.com. It has a good collection of old Hindi movies that can be streamed for free. Enter your search terms in the search box to find a list of available movies. Some of the popular movies are shown on the home page itself. The site is not entirely free, as some of the movies require a subscription.