How do you create trial version of your software?

Question

You know those annoying 30-day trials that let you see what the software is like before buying it? How can you create those without parting with £50 for some basic software created by someone in there to-much spare time?

Answer 1

First, I'd like to say that it would be best to distribute the program as 'cripple-ware.' That is, you have some part of your program that is missing in the trial program. Don't just disable a feature because a program cracker can re-enable the missing features. This won't save you from those @#$@#$# stupid file sharing networks, but it is more effective than distributing your complete program.

Your installation program needs to create a registry entry in some obscure part of the registry. When the user uninstalls the program, the uninstaller doesn't remove the key. There is a Windows function which can get the creation date of a registry entry, so this is how you can tell if a trial period has ended, or if the program was previously installed. For better security, your program should add additional checks with the registry (like the licence info), which will make the program more difficult to crack.

As for the key generation itself, your website can generate a key and keep a copy of it. (Any program updates would require a check for a valid key. You can also have the program do a key verification check with your web site once a month.)
There's also the option of putting part of the key-generation code in the program and have the key-generation based on the computer's hardware too.
Creating an algorithm for a key/serial number is easy enough, so there's no point in explaining that.
(If you're not familiar with creating web sites, well, then that's something you'll have to look into.)

Answer 2

The hard part about programming this in is that fact that if you store it on their machine, that there's a possibility they can find it and delete it (or change it to a much later date). You could place a date string value in registry. People are so scared about going in there, they'd never find it. You could include it in a serialized object or hide it in a file that doesn't look like it would harbor a date of expiration. Or (although there's a lot of limitations with this one) you could have their computer connect to a server and pass to the server the date your application was installed. Each time they turn the program on, check the date on the server. The issues are that they could block the port you use to talk to the server, they may not have the internet, firewall prevents the server from talking back and other downsides that you may not run across until you actually try it.

Answer 3

Softwares many times save keys interior the registry to be attentive to what's being executed. It makes an expiry date itself (like 30 days ) and famous out the date on which it became put in and straight away warns you after the time. one way ro re-use the demo version is to discover and delete the registry key of that distinctive application on your computing gadget. whenever you run an .exe report, some keys are stored interior the device so as that each and each time a extra moderen version is put in it identifies the previous version and makes merely few differences to place in the hot version. the value of the keys is replaced each and each time a sparkling application is put in or configuration settings are changed. First, looking the particular registry key is somewhat problematic, and whether found this is definitely necessary to delete all the keys linked with the applying or once you get admission to information superhighway, the help would be despatched over to the applying distributors (making differences in a application is unlawful). in case you employ Registry Editor incorrectly, you may reason severe issues that could require you to reinstall your working device. That way even uninstalling the demo version and re-downloading and re-installation won't help as there are registry keys put in from the applying(as i attempted doing it and ended up dropping time in downloading and dealing the applying).

Answer 4

normally you could just have a algorithm to generate the numbers for the end users... and have the program which accepts certain code, within your program if they register it, you give them a working number.. and the program you have can generate the number part

or other things like a hidden file, or checking the CPU id + time , date.

or another way is to use a dongle.. or cd check etc.

Answer 5

A very simple way (which is easy to crack if you know how) is to put a file or a Registry key in that has the date it was installed. Have the program read the file or key and if it is over 30 days, end the program.