The first line of defense is to make sure the computer's operating system has the appropriate and current updates. Check Microsoft Security and Critical Updates or Apple's Software Updates. Next is a good antivirus program and an additional (and preferably independent) anti-malware program, which will be close to worthless unless you are (or it is automatically) downloading and installing the latest virus definition files. Java, Adobe Flash and Reader should also be current. These are the most common ways for a computer to be compromised. We often find computers with some of the best software available to combat these problems, but because the software was not updated or used on a regular basis, the computer runs slow, or is infected. Now that all software is up to date, the next consideration is a firewall. There are two kinds, software firewalls like the one built into Windows and hardware firewalls like those built into Gateway Routers. The Windows XP (software) firewall is so poor, it demands an independent firewall program to be installed. Vista is not much better. However Windows 7 and 8.x both offer sufficient protection as do many other third party programs. Most small businesses and residential users will find the best solution is built into their current router, as long as they know it has been turned on. Most routers offer stateful packet inspection (SPI) combined with network address translation (NAT) - however making sure they are turned on requires logging on to the router and checking the appropriate page. If you suspect a virus or other invasive program, you can scan your system online or with retail antivirus software. The web links listed in Online Help could be helpful in determining the problem or in confirming your system is clean, if you are in doubt. Please follow the manufacturers directions. Please note that not all malware can be reliably removed from an infected computer, particularly with multiple infections involving rootkits.
