Hi Edgar, Reading your post has me a little confused.....your statement implies you are trying to register various versions of Swapper.  Swapper is the means to register different Visilogic versions.  It is primarily used for when you want to work with older versions of Visilogic for compatibility with PLC installs done at some point in time past.  Using modern versions often creates the need to update a host of things, or do major mods to a program because of the constant improvements Unit