If you install TILLvisION 4.0 on a computer on which no TILLvisION program was installed previously and you want to register your TILLvisION extensions (e.g. TILLvisDECO, TILLvisTRAC) with license keys provided with your TILLvisION 3.x version (the keys were delivered on floppy disks), you have to adapt the license reg-files to TILLvisION 4.0 since the registration path has changed. The procedure is described in the "Setup" part of the Software Documentation delivered with the TILLvisION 4.0 release CDs.