It is a Stand-alone autocad 2002 licence. there seems to be no pattern to when the re-authorization requests occur appart from that it allways happens as I launch the program not while using it. However it does occur at any time as I may have on ocasions been using the software for several hours, before closing it down for 5 mins and when I try to start up it fails. the last few request codes that I have used if they are any use are: (edited out)and the serial No. is: (edited)