Humm, ... You now, each blank CDR/CDRW have a unique (for EACH CD) sector, called ATIP, containing information about manufacturer, disc etc. ATIP info can't be copied to other disc, this new disc will have own ATIP. Maybe is possible, before burning final exe, read this ATIP and put this info in some way into compiled pte show. Before running pte executable need to read this ATIP and check, if this is the same. If not, exe will not run. This is not industrial method, but this can be a way to protect some individually distributed discs. What you say, Igor, about this? I don't know, if all cd drives can read ATIP - target pc need to have some correct drivers installed (most all have WNASPI32.dll). Maybe this can't be done, but maybe Igor? elIvarz