When hackers write malicious code designed to infect and corrupt a targeted computer system, they tend to exploit programs most widely used in order to target the greatest number of people. Microsoft's Windows XP is one of the most common PC programs, and thus is often attacked by hackers. Those who have Windows XP installed on their computers should be extra vigilant about taking steps to protect their systems, including installing a router firewall and making backup copies of their important data.

Installing a router firewall on computers running Windows XP is one way to prevent hackers from exploiting Windows XP and breaking into a system. A router firewall is a piece of hardware that blocks unauthorized software and hackers from accessing a computer without permission. The router firewall logs outgoing traffic and monitors incoming traffic to ensure its safety. Some ways to maintain the security of a router firewall include:

1. Test the features of the router firewall after installation to make sure it does what it says it's going to do.
2. Keep it secure. Reset the password and configure the router's security features periodically.
3. Keep it updated. Check frequently for updates to make sure the router firewall is functioning at its maximum potential.

In the event of computer invasion or infection by a hacker through Windows XP vulnerabilities, it is important to have taken advance precautions to protect any important files or  data. Performing routine backup on the system can limit the amount of data loss incurred by such an invasion. Some points to consider when performing a backup include:

1. Performing backup routinely and periodically to improve the chances of data recovery.
2. Using an automated backup system instead of a manual one, to avoid human error.
3. Making two or more backup copies to further ensure data safety.
4. Using a data compression system for large amounts of data.
5. Using independent indexing for multiple media backup to optimize individual data recovery.
6. Implement an effective recovery strategy; for example, make sure the program that will read the backup files is stored separately and ready to reinstall in the event a hard drive format is performed.

Windows XP and other Windows platforms will continue to be prominent hacker targets based on the sheer number of people who use Windows. Creating backup of important files and installing a router firewall on systems that run Windows XP will help keep a Windows XP user's data secure.