User registration via serial number in a database

Hi,

I have a program which i am working on which i would like to be able to get users to need a serial number to use the program.

It would need to be written in such a way so as to only show up until the user enters the number and then not show up again whilst it is installed.

Furthermore the serial numbers would need to be compared against a database to ensure they exist and preferably have the ability to revoke serial numbers.

I hope this is possible. I am using vb6.

Thanks in advance of any help.

These checks are very easy to bypass in VB. Its simply a matter of changing 1 byte in the .exe file and your in. The average user wont have a clue how to do that though so if you want to add that kind of protection you can do.

You could consider encrypting some important data and the serial number can be used to decode it.

Storing the serial number is usually done in the registry. I think even Microsoft products store it there but ive heard about compatibility issues with Vista so you may want to store it in a file instead. When your app loads you check for the file and automatically insert the serial if you can. If not then you prompt the user for it.

How do you want to compare against a database? Do you mean a central database on your server or a local one?

I think the idea of putting it in a file like you said would be the best idea. How would i go about doing that?

Thanks

File Handling (http://www.garybeene.com/vb/tut-file.htm)

For this i think you will just need input/output but i like using the binary file operations (described at the bottom of that page) for more complex things