Instantly block internet access with NetDisabler

Freeware developer Sordum has unveiled NetDisabler, a freeware Windows application which can disable and restore internet access on demand.

The program stands out immediately for its use of three web-blocking techniques: disabling the network adapter, blocking via DNS or using the Windows Firewall.

You’re able to use and combination of these tricks to disable your internet connection, increasing the chances that NetDisabler will work for you, and making it harder for others to bypass.

The program is a sub-1MB download which unzips to a couple of executables only (32 and 64-bit). There’s no installation required, and no drivers, Windows services or anything else left permanently running in the background.

Basic operations are very simple. Launch the program, check boxes to select your blocking methods (devices/ DNS/ firewall), click "Apply" to turn web access off. Repeat the process, clearing the check boxes, to restore access.

All three blocking methods worked on our test system, though with slightly different effects. Disabling network adapters gave "can’t connect" error messages almost instantly, but using the DNS and Firewall blocking techniques left apps trying to connect, and there were no alerts until they timed out. This might take a while for some applications, so be patient.

A simple command line interface allows using NetDisabler from scripts. You could have shortcuts which turn internet access on or off with a double-click, for instance, or automatically disable web access before you launch a specific application.

It’s also possible to password-protect NetDisabler, making it more difficult for others to run the program and undo your settings. It won’t keep experts out for long – and might cause you some hassles if you forget the password – but should be enough to defeat non-technical users.

We’ve seen similar tools around, but NetDisabler’s support for three web-disabling methods, combined with its optional command line interface, helps the program stand out from the crowd. Give it a try.

NetDisabler is a free application for Windows XP and later.