1. A method for preventing illegal use of software, comprising: checking, by a data storage device controller, whether the software is properly installed and not illegally modified on a data storage device; blocking, by the data storage device controller, a launch of the software, if the software is not properly installed or illegally modified on the data storage device; checking, by the data storage device controller, whether the software has to be paid for use, if the software is properly installed and not illegally modified on the data storage device; allowing the user to use the software normally, if the software is free for use; checking, by the data storage device controller, whether a user has already performed a payment process, if the software has to be paid for use; blocking, by the data storage device controller, the launch of the software, if the user does not perform the payment process; determining an available time period of the software usage for each user of the current personal computer in a case the user has already made the payment, and allowing the user to use the software normally; prompting the user to perform the payment process once more in a case of the used time period longer than the determined available time period; and terminating, by the data storage device controller, an execution of the software, if the user does not perform the payment process in time.