Lately I have had a lot of requests on how to install Sun’s Virtual Box on Backtrack 4. Virtual Box is a virtual environment similar to Vmware but it is free. Virtual Box will allow you to run other operating systems on your host. This can be useful for security because you will not harm any one or any thing will practicing.
It should be noted that adding third party repositories to any distribution can cause problems. That being said, many of us have downloaded and installed Virtual box using this method with out any problems.
Below I will outline the few simple steps to install Virtual Box