>Çetin, what would you use for a serial number - for protecting the software? Would it be practical to use the serial number of the network card - if available - and, perhaps, the HD serial number, otherwise?
>
>Hilmar.

Hilmar,
How could I say how would I do it really :)
Any newbie hacker would try first volume serial as it's the FAQ.

A net card address is unique compared to HDD (and really unique if modifiers weren't in scope such as novell boot configuration). However retrieving it in all systems with VFP is a trivial task IMHO.

Hardware at customer site could change frequently than we might think. I would base it simple but effective software solutions (yes not durable to format but I don't want it to be). ie: This is too much simple but simply stops average copiers :
-Create a dummy file in a common dir (such as windows\system) with a not surprising to see name (ie: wbemmofcompiler.vxd).
-Check its existence
An average user would never dare to check/alter there. A newbie hacker would but might easily miss if that's needed for something else or not. He knows changing HDD serial does no harm.

Another simple one is to change - with its graphical representation chr(0xad) in say partition area (message strings). This is highly possible to miss.
etc.
Cetin