I want to have the computers in my office secured such that no employee of mine should visit social networking sites and pornographic sites. I wanted a batch file which will disable access to websites I add address of so that they are inaccessible. Also the batch file should provide feature such that on activating it, it will again give access to the websites that are blocked. Sometimes, a social networking site too provides important information, which is why I want such a batch file. Can someone tell me if such a batch file is available, if yes, where to find it?