Install And Update Anti-Virus Software
Always protect your computer by using up-to-date anti-virus software that is capable of scanning files and e-mail messages for viruses.This will prevent your files getting corrupted or lost and also prevent your computer from getting infected with the virus.
Anti-virus software protects you from Trojan horses. Trojan horses are sent to computer systems typically through e-mail. They are particularly dangerous because they have the potential to allow others to gain control of your computer system remotely, without your knowledge or consent. These programs can capture and send sensitive information stored on your hard drive to any other person who has gained remote access to your computer.

Use A Personal Firewall
Any computer or device connected to the Internet that is not properly protected is vulnerable to a variety of malicious Internet intrusions and attacks. This applies to all users of cable modems, digital subscribe lines (DSL) and dial-up lines. However, cable modem and DSL users are particularly vulnerable because both connection methods provide "always-on" connection capability. The likelihood of a malicious person entering your computer increases significantly the longer your computer is on and is connected to the Internet.
A personal firewall will help protect you from intrusion. Firewalls create a barrier between your computer and the rest of the Internet. A firewall can be a hardware device, a software application or a combination of the two. Firewalls can prevent malicious attacks and block certain types of data from entering your computer or private network. They can also be set up to alert you if anyone tries to access your system.

Keep Your Browser And Operating System Up-To-Date With Software Updates
The software you use and the Internet itself can impact the security of your online activities. Therefore, you should watch for security bulletins that warn you of various security "holes" or "bugs" that may impact the software and web browser you are using. It is very important to check the websites of your operating system and web-browser vendors for software "patches" and "updates". Some operating systems and software can be configured to automatically check for new updates.

Activate A Pop-Up Blocker
Several free, publicly available programs exist that will block all pop-up windows from occurring while you are online. You can download such programs from the Internet.

Scan Your Computer For Spyware Regularly.
Spyware and adware are programs that monitor your Internet activity and potentially relay information to a disreputable source. Free spyware-removal programs are available on the Internet.

When You Are Not Using Your Computer, Shut It Down Or Disconnect It From The Internet. Do not leave your computer unattended for a long time. When not in use, disconnect from the Internet or shut it down.