If you regularly download music, software, pictures and file attachments, you can easily get virus and spyware infections...

There are many ways that you can infect your computer by downloading or installing files. Opening pictures, links and file attachments in email messages can infect your computer, even if they are sent to you by friends. Installing programs from burned (home-made) CDs that are borrowed from friends or given to you could contain viruses. Copying word processing and spreadsheet files from a company network could infect your computer if they have viruses. Upgrading software that you downloaded from the web could be risky. Sharing files with computers around the world can easily get your computer infected.

A file that you download might be what you were expecting, but it could also carry malware infections into your computer, such as spyware, viruses, worms and other dangerous hidden programs. Before you download any files from the web, you need to ensure that your computer is secure. As I've noted in previous articles, have anti-virus and anti-spyware installed, keep them updated, and perform regular scans. With many of these programs, in Windows you can right-click on a file you just downloaded and scan the individual file for viruses or spyware. All computers should have at least a software firewall installed and turned on, even if it's just the built-in Windows firewall, and any computer that is connected to broadband internet at home or in the office should also have a router with a built-in firewall, and it should be turned on and working.

You should also be sure to keep Windows updated with all of its latest security patches. Don't ever ignore Windows updates that want to be installed, you should save your work, close your programs, and install Windows updates. When they are finished, then you can reboot your computer and get back to work. Versions of Windows that have been made since 2000, including Windows ME, Windows 2000 SP3, Windows XP and Windows Vista are capable of installing updates automatically, and automatic updates can be activated and configured in Control Panel. Older versions, such as Windows 2000 SP2 and earlier, Windows 98, Windows 95 and Windows NT, must be manually updated by going to the Windows Update site, where you must select, download, and install Windows updates yourself. Even if you use a slow dialup connection, it's important to keep up on Windows updates.

You should always wait and take the time to read before you open file attachments or click on links in emails. Note that online banking sites will never send you files or links on their own, a previous action or request that you've made may generate a bank email to you, but always verify with your bank first before opening anything in these emails. Of course, never open file attachments or links that come to you from strangers, either in emails or in instant messages. If someone you know sent you links or file attachments in an email or instant message that you did not expect, always call this person first to verify that they actually sent it, as it could be fake, and you should especially delete the message if they did not know it was sent.

When downloading a file attachment or a file from a web site, click Save instead of Open. When I save files, I will usually save them to my Windows Desktop. If the file is a program, then I'll double-click and install it from there. If I want to keep the downloaded file, I will then move it to a folder in My Documents for safe keeping. Before downloading a file, save all of your work and close programs first, to help avoid losing data in case a problem occurs. If you can't remember the last time you backed up your computer, consider doing it now. Installing some software programs might erase data on a computer (though not always intentionally). After you've saved a file to your computer, double-click the file to open or run it. If your anti-virus program detects a virus, don't continue, quickly delete the file, and delete the message if it was attached to an email.

You should beware of certain file types of downloaded programs. No file type is completely safe from infections, but photos, music, and text files with names ending in .jpg, .gif, .mp3, or .txt are less likely to be dangerous. Be very careful with all other file types, such as file names ending in .exe, .com, .bat, and .vbs, they can contain code that could infect your computer.

If you've downloaded a program and you're installing it, carefully read the license agreement, and if you agree with the terms, click I agree. Programs bundled with spyware will often specify in the license agreement that they will monitor your surfing habits or display advertisements. If you click "I agree," you're giving the software publishers permission to track your computer usage or to display ads. Be sure to follow the directions on your screen if you are installing a program.

Popups, banner ads and web site ads are another security risk. Beware of clicking links that include a request for confidential information, for example, one that says "Click here." Never click "Agree," "OK," or "I accept" to get rid of a pop-up advertisement, an unexpected warning, or even an offer to scan or remove spyware or viruses. Instead, close the window by clicking in the upper-right corner. If the window won't go away, your computer could already be infected. You should only download files from reputable sites. Never download files from web sites if you were referred to them by email or a message from an unknown source.

All web sites that contain adult, pornographic, gambling or casino content contain some form of spyware and viruses. I've had to clean up way too many computers because one or several people using the computer were browsing porn sites or nude photos, or because they were playing games in online gambling sites. Be wary of any site that has offers that seem too good to be true, as in most cases they are probably fake and contain infections, or that want to obtain personal information about you. Many times, filling in your mailing address on forms in these sites will cause even more junk mail to be sent to your postal mailbox, and might even get you included on cold-calling sales lists, etc.

You should always respect the law. Remember that all music, software, games, photos and videos that are copyrighted by their artists are someone's original works. If you download and share these files without payment or permission, especially via P2P (peer-to-peer) file sharing sites, you can risk serious legal troubles and lawsuits for distributing copyrighted materials without the artists' permissions. This could lead to huge fines or even jail time. Also note that there are some files, such as certain kinds of pornography, that are illegal to intentionally download, view, or own. Teens and college kids have been sued for thousands and sometimes millions of dollars for sharing thousands of illegal files. People have gone to jail for downloading and sharing child pornography.

Don't install or use file-sharing programs. Limewire is an example of a file sharing program. When you use file-sharing (a.k.a. P2P, peer-to-peer) programs to trade music, video, and other files on the internet, you make some of your files available to others using similar software. Using some file-sharing programs like Limewire can also mean leaving an open back door through your computer's security, allowing anyone access to all of your personal files on the internet. File-sharing programs can also carry viruses and spyware, and continually infect your own computer as well as all of the computers that you connect to. They can lead you to download illegal files, songs, software, pornography and copyrighted files that can get you into a lot of trouble. And once these file sharing programs are installed on your computer, they can be impossible to remove without reformatting and reinstalling Windows, which means that you lose all of your data.

If you believe that your computer has been infected by downloading or sharing files, contact me for an appointment to clean up and protect your computer. There are also books available that will tell you about spyware prevention.