Older versions of operating systems cannot be secured against modern Internet security threats.
Windows XP and Mac OS X both have built-in tools for keeping track of critical security updates to their operating systems. You should configure these tools to download and install critical updates automatically. Doing so is easy and, once set up, requires little or no additional input from you.
1. Choose the Start Menu
2. Choose Control Panel
3. Choose the "Windows Update" icon
4. On the left choose "Change Settings"
5. Ensure that the computer is set to update automatically. Note: The default setting is "Install updates Automatically (Recommended)"
Mac OS X
Mac OS X automatically checks weekly for software updates provided that you have an Internet connection. You can choose a different schedule, or you can check manually if you don’t have a continuous Internet connection. If Software Update finds an item to download, it appears in a list. Click on an item to get a description before downloading it. If you see updates that you will never use, such as a language you don’t speak or drivers for a printer you don’t own, choose Make Inactive from the “Update” menu. You can always view the hidden updates, should you discover you need them in the future.
To get Mac updates immediately: