A computer program product and system for allowing license tools to detect the installation of applications that are not physically installed on a machine when an Application Virtualization Environments is used. In one embodiment of the invention, the license tools may further detect application usage. In one embodiment of the invention, a virtual installation signature may be defined. Agents in a target computer may be used to compare the virtual installation signature of an application with a localized list of potential applications to detect whether the software is installed on the target computer.