A method for enabling use rights on a file, which is stored on a storage medium together with at least one other file and is provided with an identifier, for use by a single computer system or by a limited number of local computer systems, wherein a central station calculates a first and second scrambled code PIN and ACW containing a key k, for decrypting the files stored in encrypted form, and a device identification number ID. The device identification number ID is changed with each new enabling operation. Once the two scrambled codes have been entered into the computer system, the computer system first calculates a new device identification number ID from stored data and uses this new device identification number ID and the first scrambled code PIN for the key k and uses the key k and the second scrambled code ACW to calculate an identifier AC for the file which is to be enabled.