my system c: is cant able to open when araise error message for access is denied what to do?

The chances are that you are trying to write to the root directory of C: - which is forbidden unless you have full admin privileges as it is your boot drive, and Vista / Win7 + will not allow changes there.

You could raise the permissions level of your app, but that is a big change in authority, and while easy to do is not a good idea. Instead, create or use a folder where you have full persion, and use that instead - it's safer in the long run!