how to protect the program?

I have developed a program, which will be installed by several users. How can I protect it, so, once installed, the users can use them on the installed pc, but not others.

before, what I did is: create a web service, when the user use it, they need verify the account by the web service. however, it needs the user always be online, which is not applicable to this case.

any existing component/system/.... that can do this.


thanks

bear

Invest in a licensing component. The one I usually recommend is Infralution Licensing System, which I haven't used for a while but found to do a good job at a reasonable price.