1. A virtual application creating system comprising: a virtual environment library block including a plurality of modules that process native application program interfaces (APIs) of an operating system of a host computer such that the native APIs are suited to a virtual environment independent of a host executed environment of the host computer, the virtual environment library block configured to find a module capable of processing a specific native API from the plurality of modules when the specific native API is called and operating the found module to process a function of the called native API in the virtual environment; a virtual application installation block comprising a virtual installation preparation module receiving position information identifying a position of setup information for setting up an application to be virtualized and information on an installation place where the application to be virtualized will be installed from a user, storing the information as variables and providing the stored variables to a specific module, and a virtual environment library insertion module creating an application installation process, in a suspended mode, using the position information, provided by the virtual installation preparation module, and inserting the virtual environment library block into a memory to install a virtual application in the installation place, wherein the virtual environment library insertion module fetches the application installation process using the position information as a location of a setup file of the application received as a factor, inserts the virtual environment library block into the application installation process to convert the application installation process to a virtual application installation process to install the virtual application, and then starts the virtual application installation process; and a virtual application execution block executing the virtual application installed in the installation place.