There are lots of parental control tools out there on the market, but if you're looking for an app designed to block the browser exclusively, you may want to have a look at Browser Lock.
As its name suggests, Browser Lock is an application aimed at parents who want to restrict their children from browsing the Internet.
While this kind of app is always helpful if it doesn't assault users with too many unnecessary options, Browser Lock cannot prevent the usage of any other Internet app, be it an instant messenger, file sharing tool or email client.
Browser Lock asks for a master password from the get go, but be aware that once you launch the app and input the password, all browser sessions are automatically closed. So make sure you save your work before double-click the app's shortcut.
The application can block the most popular browsers on the market, including Internet Explorer, Firefox, Opera and Safari, regardless of the Windows version running on your system.
There are only a few configuration options to select the amount of time with Internet access, but nothing too difficult to get you into trouble.
As mentioned, an average computer user should be able to figure out the purpose of each option in a second, while Browser Lock remains light on hardware resources all the time.
Overall, Browser Lock serves its purpose perfectly, but some warnings and more instructions in the main window could come in very handy to all users.