Software Utilility

Utility software (also known as service program, service routine, tool, or utility routine) is a type of computer software. It is specifically designed to help manage and tune the computer hardware, operating system or application software

Virus Protection
The term "virus" is used to describe various types of malicious software that can affect your computer. Viruses work in different ways and have varied effects, but almost all can destroy data or prevent your computer from working properly. Some are merely an inconvenience; others will destroy particular files types or even erase your entire hard drive. Viruses can be written for any operating system, but most are written for and affect the many versions of Microsoft Windows. While viruses used to be passed predominantly from user to user via floppy disks, the most common method of receiving viruses these days is from an email attachment. The only attachments that are potentially harmful are executable files (.exe, .com, .pif, and .bat files), certain scripts (including .vbs and java scripts), and documents that allow macros to be run (generally Microsoft Word and Excel files, .doc and .xls respectively).Because new viruses are created and distributed daily, virus protection programs rely on frequent updates (called definition or DAT files) to remain effective. If your computer is infected with a virus and you do not have anti-virus software installed or do not have a recent update, you may not be able to install or update the software. In such cases, more specialized virus recovery programs will be necessary to repair the damage.

Firewall

A firewall is a system that secures a network, shielding it from access by unauthorized users. Firewalls can be implemented in software, hardware or a combination of both. When your computer gets an unsolicited request, Firewall blocks the connection. If you run a program such as an instant messaging program or a multiplayer network game that needs to receive information from the Internet or a network, the firewall asks if you want to block or unblock (allow) the connection. You should see a window like the one below. Firewall is a critical first line of defence to protect your computer against many types of malicious software. It helps block computer viruses and worms from reaching your computer.
It can stop many kinds of malware before they can infect your computer or other computers on your network. It helps in protecting other operating system resources if they behave in unexpected ways-a common indicator of the presence of malware. For example, if a component of windows that is designed to send network messages over a given port on your PC tries to send messages by way of a different port due to an attack; firewall can protect the malware from spreading to other users.