3rd party tool for creating a time limit on an application.

[witchblade]

Does anyone know of a 3rd party tool that will allow me to install an application (built in VB) and place a 30 day time limit on it?

 

[zemp]

I don't know of any off hand. But you can search at

http://www.planetsourcecode.com

or

http://www.a1vbcode.com

to see if someone has posted something like that. Also you can search google (or other search engines) for 'trialware' (I think that's the name for it.

You can also do it yourself. You will probably need an encryption algorithm and knowledge of some API calls. I have an ecryption module that I use. When a user first installs an application I generate a serial number (unique to the app and computer combination) and hide it in the registry along with the date installed. Them I just check against the date installed and after a specified period of time the app quites. To continue or override I can provide a registration key when they purchase. It Is simple and by no means completly secure, but it is enough for the average user.

If you don't find anything and are interested in what I have let me know. Thanks and Good Luck!

zemp

 

[tedsmith]

I use a simple idea without any extra programs. I just append six numbers (120702 for 12 July 2002) representing the date to the end of the exe file. It does no damage.
When first shipped the exe doesnt contain any numbers so I have a routine that detects this and says it is a trial version and it appends the date at the first time run.
Next time it is run it finds numbers and if the date is past that number it says your time has expired or how many days you got left if under 30.
When they enter a password key it makes the numbers 999999 so from then on it is a legit copy forever.
I also check the archive bit when I first run it and wipe the numbers so any copy immediately returns to a trial version!
You have to use format when comparing to change the date format back to normal(ddmmyy( from the USA version(mmddyy) if you ever sell it in countries like USA that dont have a world standard date.

 

[witchblade]

Thank you so much! Great information!!
I'll let you know if I need any further information.