A computer-implemented method for executing virtual applications within a host operating system, the method comprising: providing the virtual application with an environment for which the virtual application was designed using available resources of the host operating system; registering for and receiving notification in response to the host operating system creating a new process; adding (350, 360) one or more fields of data to a token associated with a virtual process that identify the process as a virtual process and associate the process with a particular virtual environment; receiving requests from one or more applications to access resources managed by the host operating system; accessing the token of an execution context and read the one or more fields of data added to identify virtualization information including information to identify the particular virtual environment associated with the virtual process; and receiving the virtualization information accessed from the token including information to identify the particular virtual environment associated with the virtual process and redirecting resource requests from a specified location to a virtual location, wherein the redirecting comprises redirecting the resource requests to the identified particular virtual environment; wherein a token associated with the new process is identified, and if the process is associated with a virtual application environment, the one or more fields of data are added to the virtual process token, and, wherein the one or more fields are added to a portion of the token that the host operating system automatically replicates to related processes of the virtual process. providing the virtual application with an environment for which the virtual application was designed using available resources of the host operating system; registering for and receiving notification in response to the host operating system creating a new process; adding (350, 360) one or more fields of data to a token associated with a virtual process that identify the process as a virtual process and associate the process with a particular virtual environment; receiving requests from one or more applications to access resources managed by the host operating system; accessing the token of an execution context and read the one or more fields of data added to identify virtualization information including information to identify the particular virtual environment associated with the virtual process; and receiving the virtualization information accessed from the token including information to identify the particular virtual environment associated with the virtual process and redirecting resource requests from a specified location to a virtual location, wherein the redirecting comprises redirecting the resource requests to the identified particular virtual environment; wherein a token associated with the new process is identified, and if the process is associated with a virtual application environment, the one or more fields of data are added to the virtual process token, and, wherein the one or more fields are added to a portion of the token that the host operating system automatically replicates to related processes of the virtual process.