Management method in a computer system, computer management system, and computer management program

A management method for a computer system for simply and more reliably preventing an unauthorized use of an application has been disclosed. The management method of a computer system, which comprises hardware, an O/S, a DLL storing a plurality of DLL files, and a plurality of application programs that use the DLL files, prevents an unauthorized use of an application, the use of which is prohibited for some users. A set of prohibited DLL files required for identifying a prohibited application is determined, the set of the prohibited DLL files is stored in correlation with use conditions, use conditions are detected when the activation of an application program is requested, set of the DLL files to be used by the application program is detected, whether the detected set of the DLL files includes the set of the prohibited DLL files in correlation with the detected use conditions, and the application program is terminated when the set of the prohibited DLL files is judged to be included.