A digital rights management (“DRM”) system is described that seeks to restrict the use and execution of certain computer program code to those hardware systems or platforms authorized by the provider of the protected software. To this end, certain computer programs (or portions thereof) are provided to authorized users in an encrypted format. When a “protected” program is to be executed, it is retrieved and stored in its encrypted format in operating system memory where it is accessible to operating system level routines (e.g., a file read operation). It is also decrypted and placed in another memory such that only the process executing the protected program has ready access to it.