Go a Punjabi website which hosts Punjabi movies. There are several websites which specialize in providing Indian music, movies and television shows to the world at large.
Register for an account. Some sites require registration while other sites allow users to simply post files. If registering for a Punjabi movie account, you will be asked to provide name and contact information. Some sites charge subscription fees while others do not.
Browse the list of movies and select one to download. After clicking on the link, your computer will begin to download the Punjabi movie. Most computers have a default media player. This will pop up when your movie has downloaded so that you can watch the movie.