What is the ruling on preparing and selling useful computer programs for students and businessmen, knowing that many of them work on pirated operating systems?

The questioner must only use software for which he has legally acquired the right of usufruct. He is not responsible for those from whom he buys his software, whether their operating systems are pirated or original, due to the Almighty's saying: "Every soul, for what it has earned, is retained" and "Every soul, for what it has earned, will be held accountable" and "No bearer of burdens will bear the burden of another." And due to the saying of the Prophet, peace and blessings be upon him: "Indeed, no offender offends except against himself." His duty towards those who infringe on intellectual property rights is only to advise them.