1. A method for virtualizing access to windows, the method comprising: receiving a request relating to a window from a process executing within the context of a user isolation scope, the request including a virtual window name, and wherein the user isolation scope is provided by an isolation environment comprising a user isolation layer and an application isolation layer; selecting, by a rules engine, a rule action associated with the request, the selection responsive to the request received from the process executing within the context of a user isolation scope, and determining that a rule action from a group consisting of ignore, redirect and isolate, is associated with the request; determining a literal name for the window, in response to the selected rule action, using a scope-specific identifier associated with at least one of a particular user isolation scope and an application isolation scope; issuing to the operating system a request including the determined literal window name; and associating a window handle with the virtual window name.