the way to set application path without touch system path

http://msdn.microsoft.com/en-us/library/ee872121%28VS.85%29.aspx#appPaths

o register and control the behavior of your applications with the App Paths subkey:

1. Add a subkey with the same name as your executable file to the App Paths subkey, as shown in the following registry entry.

   HKEY_LOCAL_MACHINE or HKEY_CURRENT_USER
      SOFTWARE
         Microsoft
            Windows
               CurrentVersion
                  App Paths
                     file.exe
                        (Default)
                        DontUseDesktopChangeRouter
                        DropTarget
                        Path
                        UseUrl