I came to know from the Fatwa I asked to Islamweb Fatwa Center that using pirated copy of software is forbidden in Islam. What will be the solution now for them who already have used many pirated copy of software?

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.

Whoever has used these programs is obliged to repent to Allaah and seek forgiveness from their owners either verbally [face to face], or by telephone, or e-mail, or by any other means of communication.  If they do not accept to let him have those programs free of charge, he should recompense them financially according to the price of those programs. For more details, please refer to Fataawa 82812, 85102 and 90342.

Allaah Knows best.