How do I enable JavaScript in Internet Explorer 5.x or 6.x? To enable JavaScript in Microsoft Internet Explorer 5.x or 6.x, perform the following steps: From the Tools menu, click Internet Options. From the Security tab, click Custom Level. The Internet icon is highlighted by default. Scroll to Java permissions, click to select High safety. Click OK. Click OK. From the File menu, click Close. Relaunch your browser. Your browser stores many of its settings. The best way to ensure changes to core function settings to take effect is to close all browser windows completely, then relaunch it.