Updating Internet Explorer does more besides adding new features -- it also applies bug fixes and compatibility patches to the system, and can replace program files or settings that have been erased or corrupted. As a result, you can fix a wide range of issues by upgrading to the latest version of the browser. As of publication, Internet Explorer 8 is the most recent version compatible with Windows XP; download it for free from the official Microsoft website at microsoft.com.
A problem with Internet Explorer locking up whenever the back button is pressed in Windows XP suggests an issue with the browser software or an associated plugin. If the problem only occurs on one specific site, the site itself is probably the cause. Troubleshoot the problem by applying the latest updates and patches, and determining if any plugins are causing the software to hang.
Updating Internet Explorer
Internet Explorer is tightly integrated into the Windows operating system, and as a result, problems with Windows -- such as missing files or outdated code -- can also cause the browser to lock up in certain situations. Make sure that your operating system is set to automatically download and instal the latest updates by opening the Windows Update section of Control Panel -- again, this ensures that any compatibility updates or new bug fixes are applied to the computer.
Checking Plugins and Other Software
A third-party plugin can also cause issues with Internet Explorer. To determine if this is the case, disable all add-ons by opening the Tools menu and selecting "Manage Add-Ons" from the list. Select "All add-ons" under the Show heading, then choose each one in turn and click on "Disable" in each case. Restart Internet Explorer. If the problem is fixed, re-enable the plugins one by one to work out which one is causing the issue. Another, separate program may also be causing Internet Explorer to lock up, so when running the browser, close any other browsers, as well as any unnecessary background utilities and services via the Task Manager tool.
If clicking the "Back" button only causes Internet Explorer to lock up on one particular website or domain, such as msn.com, it's likely that the problem lies with the way the site is coded or the way it runs in Internet Explorer. Visit the site in an alternative Web browser to see if the issue persists. If possible, contact the site developer or webmaster directly for further troubleshooting advice. If you are unable to resolve the issue, consult the troubleshooting articles and tools provided by Microsoft on its official website.