hello,
I want to apply concept of Net Protector or like that in my application.
so plz help me how can apply that concept i.e my exe. place only one PC at time. When after formatting or uninstall exe. then 2nd time they also not install my exe on same PC

The only way in which to accomplish this is a self deleting install program, of which, does not exist at the moment. So good luck in creating it and in the future, you are not posting a code snippet, you are posting a question....

Good Luck