Trial Version

  • Thread starter Thread starter Dean
  • Start date Start date
D

Dean

I have a program I want people to be able to try (limit
15 uses) before they buy. How can I make my program
terminate if no serial number is present the 16th time it
is run. I have thought of using files, but they are
easily spoofed. I want to make sure it still works if
the software is uninstalled and reinstalled. Please help
me if you can.

Respectfully,
Dean
 
I have a program I want people to be able to try (limit
15 uses) before they buy. How can I make my program
terminate if no serial number is present the 16th time it
is run. I have thought of using files, but they are
easily spoofed. I want to make sure it still works if
the software is uninstalled and reinstalled. Please help
me if you can.

Respectfully,
Dean
Click to expand...

Just write your "trial-counter" to the registry. And on uninstall don'T
remove that key.

Yes, I know, it would be easy to hack that, but for the normal average
shareware user it should be enough.

You could also write a webservice that will be contacted everytime the
programm is started, but that would require the user to be permanently
online.

--
------ooo---OOO---ooo------

Peter Koen - www.kema.at
MCAD CAI/RS CASE/RS IAT

------ooo---OOO---ooo------
 
What you can do is keep some encrypted count in the
registry and at the same time, in a file somewhere else.
Just check for the count in these two locations when the
program is started. This makes the cracker somewhat
diffiult. But an experienced cracker can still crack.

Use System.Cryptography namespace for encryption.

HTH
Sunil
 
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