What is the ruling on someone who downloaded a free operating system (Ubuntu) and other programs (video, games, images) via the Firefox browser, which was previously downloaded using the Internet Explorer browser found on a pirated Windows system, knowing that pirated Windows is unlawful?

If a person repents from infringing upon the rights of others and starts using free versions of software, then he is not required to purchase original copies of what he used previously before repenting. There is no blame upon him for benefiting from the work he produced using pirated software.