Quote Originally Posted by VBprogrammer2006
Is it posible to set time limits on use of the program (ex: 365 days)
and then force to repurchase (date has to be able to be changed by LGCC)

Please help
If posible please leave examples or links to examples to posts that will help

thanks
VBProgrammer2006
If you decide to use a method simular to this one that JonnyP pointed out before. In the unlocking key you could include an Expiry date and checksum (To make sure they cant fool with the key). The key is saved in the registry, and can be checked at every application startup.

If the program has expired you could then erase the Key from the registry, and disable the program.. Keeping track of entered keys can also help to prevent the user from turning back the date on the system and entering the old Key ( I use this method for a application that no longer has support and key updates.. )

There are a number of methods to do this.. but if your looking for one where the user cannot muck around with it. the date entry must be encrypted. The checksum must be part of the key and not a seperate entry.
(Another method I used to gain access to a application that allowed you to enter a date and 4 digit validation number.. took me 2 hours to find a validation code for the date 2020/12/31 <--- this is a small hobby of mine )

Gremmy..