How to disable Java on a PC, Mac and in a web browser

Java is a technology that can be used to improve websites, perhaps by including an interactive game to online chat tool. A Java plug-in for your web browser can therefore be useful, but it’s not essential. This is probably just as well, because Java has recently been shown to contain serious security vulnerabilities.

These potentially allow hackers to install malware on a computer running Windows, Mac OS X or Linux. Currently, the only sure fix is to uninstall Java, completely disable its web browser plug-in component (Java applications that run outside web browsers are unaffected by the issue) or ensure that it’s kept up to date automatically. This Workshop explains all three.

Read more: Computeractive news | Java articles

Step 1
Before attempting to reconfigure Java, confirm that it is installed by visiting the Oracle Java test page. This works no matter what operating system or web browser is being used, but you may need to enable Java if prompted by the web browser. If the message ‘No working Java was detected on your system’ appears along with a Free Java Download button, the computer does not have Java installed and the rest of this workshop can be safely ignored.

Step 2
Unless there’s a favourite website you know for sure that requires Java, Java for Windows can be safely uninstalled. In Windows Vista and 7, this is handled with the ‘Uninstall a program’ option in Control Panel; in Windows XP, the same option is called Add or Remove Programs. In all versions of Windows, find the ‘Java…’ entry in the list of installed programs (‘Java 7 (TM) Update 7’ is the latest version but you may have an earlier version installed, or even several versions), click to select it and click the Uninstall button in Windows Vista and 7, or the Remove button in Windows XP – and then follow the prompts.

Step 3
If there’s any uncertainty about the need for Java in Windows, it’s simpler to disable it within any web browsers, then it can always be re-enabled. In Internet Explorer (IE) select Manage Add-ons from the Tools menu in IE8, or via the toolbar cog icon in IE9. When the dialogue box opens, look for the Oracle America, Inc. entry in the list of Toolbars and Extensions, then click to select the first ‘Java…’ entry. Click the Disable button at the bottom right of the dialogue box and repeat this for any remaining ‘Java…’ entries that are still enabled. Click the Close button to finish.

Step 4
In Google Chrome for Windows and Mac OS X, click the spanner icon and then choose Settings. Scroll to the bottom of the page and click the ‘Show advanced settings’ link. Scroll down to the Privacy section and click the Content settings button to open a pop-up window. Scroll down this list to find the Plug-ins section and click the ‘Disable individual plug-ins’ link below it. A new tab will open – look for Java in its list of plug-ins and click its Disable link.

Step 5
In Firefox 3.6 or later for Windows and OS X, select Add-ons from the Firefox button in Windows, or the Tools menu in OS X. When the Add-ons Manager tab opens, click Plugins in the list on its left-hand side. Look for any ‘Java…’ entries in the main window pane and click the Disable button next to each one.

Step 6
In the Windows version of Apple’s Safari web browser, select Preferences from the cog icon, or from the Safari menu in Safari for Mac OS X. When the Preferences dialogue box opens, click its Security tab and click to clear the Enable Java option. In Opera for Windows, first select Show Menu Bar from the Opera button. In Opera for both Windows and OS X, then select Advanced and then Plug-Ins from the Tools menu. When the Plug-Ins tab opens, click the Disable option next to all entries for Java….

Step 7
Unfortunately, completely uninstalling Java from Mac OS X is a technical nightmare, but it can be disabled at the operating system level – and that’s what matters. Open a Finder window, click the Applications folder in the Sidebar and the click to select the Utilities folder in the list that appears in the main Finder pane. Double-click the Java Preferences icon to open the Java Preferences. When the dialogue box appears, click the General tab and click to clear the ‘Enable applet plug-in and Web Start applications’ box. Java can be enabled at any time by repeating this step, ticking the box instead.

Step 8
Steps 3 to 6 can be repeated to enable Java in any particular web browser as required, but if Java is used regularly, this is inconvenient. In this case, it’s better to leave Java enabled and instead ensure that the latest version is always installed automatically (though as recent events have shown, this doesn’t guarantee security – so proceed at your own risk). In Windows XP, Vista and 7, start by opening the Control Panel. In Windows Vista, select Classic View in the left pane of the Control Panel window; in Windows 7, select Large icons from the dropdown menu at the top-right of the Control Panel window.

Step 9
In all versions of Windows, double-click the Java icon to open its own control panel. When the Java Control Panel window opens, click its Update tab and enable the Check for Updates Automatically option. Click the Advanced button next to this and, when the dialogue box opens, select Daily as the update Frequency and a suitable time from the dropdown list next to it. Click the OK button and Java will now check for updates daily and display a notification when one is ready to be downloaded and installed.

Step 10
Java for Mac OS X lacks an automatic update option, but Java for all operating systems can be checked for security issues by visiting a website that shows whether your Java version can be exploited in any web browser. This site tracks known Java security issues and will warn when an installed version is at risk and/or is out of date, and link to the appropriate download. The most recent version of Java can always be downloaded from the Java website  – ‘Version 7 Update 7’ is currently the latest, most secure, version.

Linux and Java
The steps for reconfiguring a Java web browser plug-in for Linux are much the same for Windows and Mac OS X. Configuring Java itself, however, depends on the Linux distribution and the version of Java being used. The latest version of Java for Linux (which may not be from Oracle, depending on the Linux distribution) should be available from the supplied package manager (Ubuntu Software Center, for example), or from Oracle.