How does a firewall prevent unauthorized access to a computer system?

Most users are interested in taking steps to prevent others from accessing their computer. Whether it be to protect yourself from malware or ensure your private information is safe, having a secure computer can provide peace of mind. The following sections detail many ways you can secure your computer against others. To proceed, you may read through each section or choose one that interests you from the below list.

  • Passwords.
  • Get a hardware or software firewall.
  • Operating system and software patches and updates.
  • Malware protection.
  • Run system scans to check for vulnerabilities.
  • Know how to handle e-mail.
  • Alternative browser.

Passwords

How does a firewall prevent unauthorized access to a computer system?

Make sure a password is set for your computer's operating system. The best way to keep someone out of your accounts and personal information is to not let them on your machine in the first place. You can always create additional accounts for guests. For additional information, see the following linked pages.

  • How to change a username or password.
  • How to create a new user in Windows.
  • Help and information on computer passwords.

Helpful password tips

  • Never keep a default password. Passwords such as "password," "root," "admin," or no password at all allow easy access to your computer or Internet accounts.
  • Change passwords often. We recommend at least once every few months.
  • Create a BIOS password.
  • When creating a password, add numbers or other characters to the password to make it more difficult to guess; for example, 1mypassword23!.
  • Do not use sticky notes around your computer to write down passwords. Instead, use a password manager.

Get a hardware or software firewall

How does a firewall prevent unauthorized access to a computer system?

We highly recommend all computer users have a firewall solution. There are two ways a firewall can protect your computer and network.

  1. Hardware firewall - A hardware firewall is a physical device that connects to your network. Often, many users who have a home network can use their network router as a firewall solution. A good example of a network security device with a firewall and other security options is the ZyXEL ZyWALL (shown right).
  2. Software firewall - A software firewall is a software program you install on your computer to helps protect it from unauthorized incoming and outgoing data. A software firewall will protect only the computer on which it has been installed. Additionally, many antivirus scanners include a software firewall. See the antivirus section on this page for more information.

Microsoft Windows firewall

If you are running any version of Microsoft Windows after XP, there is a firewall built into your operating system.

  • How to enable or disable the Microsoft Windows Firewall.

Other firewall programs

If you are not using the Windows firewall, a hardware firewall, or a firewall that is part of your security software, you can also purchase a standalone firewall program.

  • Zone Labs Zone Alarm

Operating system and software patches and updates

How does a firewall prevent unauthorized access to a computer system?

There is no such thing as perfect software. Programs often have compatibility issues or vulnerabilities that compromise your computer's security. Software patches, updates, and drivers are made available, often for free, to consumers to help keep a software program and operating systems running properly and securely.

A program with no method of checking for updates requires you to verify the program is up-to-date. Often this can be done by visiting the website of the developer who created the program. A listing of third-party companies and links to each of their pages is on our third-party support page.

  • How to update a Microsoft Windows computer.

Malware protection

How does a firewall prevent unauthorized access to a computer system?

Trojans, viruses, spyware, and other malware can monitor your computer and log keystrokes to capture sensitive data, such as passwords and credit card information.

To help protect your computer from these threats, we suggest installing antivirus and anti-spyware protection programs.

  • What are the currently available antivirus programs?
  • How to prevent or fix a web browser being hijacked.

Run system scans to check for vulnerabilities

Several online sites help check computers for potential threats. For example, the service below scans your computer for vulnerabilities.

Gibson Research Corporation - The Gibson Research Corporation, or GRC, is operated by Steve Gibson. It offers information and advice about network security and several tools to help test for vulnerabilities in your computer or network.

Know how to handle e-mail

How does a firewall prevent unauthorized access to a computer system?

Today, e-mail is one of the most popular features on the Internet. Being able to identify threats sent through e-mail helps keep your computer and your information safe. Below are some of the most common threats you may encounter while using e-mail.

  • Attachments - Never open or run e-mail attachments from addresses with which you are not familiar. Viruses, spyware, and other malware are commonly distributed through e-mails that have attachments. For example, an e-mail may want you to open an attachment of claiming to be a funny video when it's a virus.
  • Phishing - A phish e-mail appears to be from an official company (e.g., your bank), asking you to log onto the site to check your account settings. However, the web page links in the phishing e-mail are sites set up to steal passwords, credit card information, social security information, and other confidential information. See the phishing definition for additional information about this term and examples of these e-mails.

Alternative browser

Before the release of Microsoft Windows XP SP2 and Internet Explorer 7.0, Microsoft Internet Explorer was notorious for security and spyware related issues. Although it has improved since then, we still highly recommend considering an alternative browser, such as Mozilla Firefox or Google Chrome.

What is firewall how it protects unauthorized entities?

A firewall is software or firmware that prevents unauthorized access to a network. It inspects incoming and outgoing traffic using a set of rules to identify and block threats.

What prevents Unauthorised access to a computer network system and acts like a gatekeeper?

A firewall is essential software or firmware in network security that is used to prevent unauthorized access to a network. It is used to inspect the incoming and outgoing traffic with the help of a set of rules to identify and block threats by implementing it in software or hardware form.

What is unauthorized intrusion and how can we prevent it?

The term unauthorized access means invading the privacy of someone's computer without their consent. Such a situation can arise if you leave your system unattended or you are using your Internet without any firewall to protect against malware and viruses.

How firewalls are used to prevent computer misuse?

The user will never know that their system has been compromised because the threat enters their computer quietly. This is exactly where a firewall help protect you. The firewall monitors all network traffic and has the ability to identify and block unwanted traffic.