1. A method for accessing resources provided by an operating system, the method comprising the steps of: (a) receiving, by an application program executing inside an isolation environment comprising an application isolation layer and a user isolation layer, a request for a resource; (b) acquiring a first identifier associated with the resource; (c) consulting a registry, responsive to the request for the resource, for an association between the first identifier and a second identifier associated with the isolation environment; (d) identifying the resource and an application scope provided by the application isolation layer on which to launch the resource, responsive to consulting the registry; (e) associating the second identifier with the resource, the isolation environment, and the application scope on which to launch the resource; (f) storing in the registry a registry key for the resource, the registry key comprising the second identifier; (g) redirecting the request for the resource to the application scope, responsive to the second identifier; (h) responding to the request for the resource using an instance of the resource located in the application scope on which the resource resides; and (i) launching, responsive to the second identifier, the requested resource in the application scope of the isolation environment.