Hi Andrews,

>I want to created a security code with the intention of creating a number of license and to the same time avoid the piracy of my application.

Since you can have the hard disk serial number, you could use it in combinaison with SYS(2020) that returns the total size in bytes of the default disk.

You can then mix the numbers/caracters in such a way only known by you. Save it encrypted on disk in a general info dbf in a field name that does not suggest this is your key reference.

You should also have the name and address of the user encrypted and print these info on the reports and the invoices if some are involved - just to make the hacker's work more difficult. They can change the serial number - if they suspect that this is the key - but having the exact number of bytes maybe a bit more difficult to obtain or produce.

Do not show any info that let the user suspect that you depend on the hard disk serial number.

Many techniques can be used. It takes some time to find the right one but it worth it.

If you find a good security scheme, you will be able to detect;
* any new installation
* any move to another computer (could auto-switch into demo mode)
* any new version change

Good lock (^o^)