Although details may vary between packages, anti-virus software scans files or your computer's memory for certain patterns that may indicate an infection. The patterns it looks for are based on the signatures, or definitions, of known viruses. Virus authors are continually releasing new and updated viruses, so it is important that you have the latest definitions installed on your computer.

Each package has its own method of response when it locates a virus, and the response may differ according to whether the software locates the virus during an automatic or a manual scan. Sometimes the software will produce a dialog box alerting you that it has found a virus and asking whether you want it to "clean" the file (to remove the virus). In other cases, the software may attempt to remove the virus without asking you first. When you select an anti-virus package, familiarize yourself with its features so you know what to expect.

There are many vendors who produce anti-virus software, and deciding which one to choose can be confusing. All anti-virus software performs the same function, so your decision may be driven by recommendations, particular features, availability, or price. See the references section for a link to a list of some anti-virus vendors.

This process may differ depending what product you choose, so find out what your anti-virus software requires. Many anti-virus packages include an option to automatically receive updated virus definitions. Because new information is added frequently, it is a good idea to take advantage of this option. Resist believing email chain letters that claim that a well-known anti-virus vendor has recently detected the "worst virus in history" that will destroy your computer's hard drive. These emails are usually hoaxes (see Identifying Hoaxes and Urban Legends for more information). You can confirm virus information through your anti-virus vendor or through resources offered by other anti-virus vendors. See the references section for a link to some of these resources.

There are over 10,000 known computer viruses. Everyday, there are thousands of infections. In this modern age, there is absolutely no excuse for not running some sort of virus scan and anti-virus software on your computer. If you choose not to, you are risking major hardware failure and data loss. One leading anti-virus suite is the Norton AntiVirus Suite.

NetZero has partnered with Symantec to provide protection against a wide variety of Internet security threats by offering security products like Norton AntiVirus Online and Norton Internet Security Online.

Windows XP Service Pack 2 is a major security-focused operating system upgrade that includes an enhanced Windows firewall and a console (Windows Security Center) to monitor the state of your computer's security. Service Pack 2 is not an necessary packs for Symantec products. If your Symantec products run on Windows XP now, they do not require Service Pack 2 to continue working

Installing Service Pack 2 will not affect Norton AntiVirus. The Windows Security Center, which is a component of Windows XP Service Pack 2, will be aware that you have Norton AntiVirus installed, but it will not be able to determine its working status due to Symantec's tamper-protection technology.

Installingand running Norton Internet Security or Norton Personal Firewall and Norton AntiVirus is a very good way to ensure your online security. To test the actual security of you computer, visit Symantec Security Check . This is a free service that checks your computer against a wide range of online threats and identifies your existing security needs.

Your Norton security products contain tamper protection features that prevent malicious code from determining their status. This tamper protection also prevents the Windows Security Center from determining the status of your Norton security products.