While viruses and worms are becoming more sophisticated, protecting yourself against them is relatively simple. Follow these tips and you should be able to avoid the worst of cyber nuisances.

Install a firewall to prevent viruses and worms getting through. This will block unauthorized access to and from your PC or your network through your computer's ports. Install a good anti-virus utility such as McAfee^® VirusScan^® Plus.

Back up your hard drive or your network drive. With CD-writers so readily available and so inexpensive, backing up has become easier and faster than before, and back-up software lets you automate back-ups, making things even easier.

Get software that takes snapshots of your system. This lets you revert to the latest snapshot when things go wrong so you can recover from a crash quickly. However, these snapshots are not back-ups of your system or files, so you still need to perform regular daily back-ups.

Do not open any emails from anyone you do not know. If you run a small business, make this a formal policy. If it's a potential business partner or someone who really wants to get in touch with you, they will call you over the phone if you don't reply to their messages.

Especially avoid opening emails with attachments. When you get an email with an attachment from a trusted source, download it onto a floppy disk. Then, scan the email and the attachment on the floppy disk with your anti-virus program before opening either. Small businesses with networked computers should have a spare PC that is not linked to the network, which they can use to scan and open up emails on floppy disks. That way only the one PC will be infected and it can be cleaned out relatively easily. This also prevents data loss.

The most highly suspect attachments are those ending in .exe, .bat, .com, .pif, and .vbs. Even Microsoft^® Office documents such as Word, Excel, or Access files should be considered suspect because macros can be embedded in them, so scan them thoroughly and open them only on a floppy disk, preferably on a standalone PC kept solely for that purpose.

Do not download applications or programs if at all possible. If you do have to download one, scan it with your antivirus application before executing it.

Visit McAfee for information on how to fight the latest viruses and worms. Often, you can download patches that will help prevent an attack.

Sometimes the federal government issues suggestions about preventing virus infections. Treat these with great caution: The Department of Homeland Security suggested network administrators cut off access to ports 135, 139, and 445 to prevent infection by the Blaster worm. Network administrators who followed this advice found that the actions caused problems when people tried to use Microsoft Outlook and Exchange. It was later discovered that the Blaster worm uses port 69 to replicate itself to other PCs on a network, rather than those ports named by the government.

If you use Microsoft programs, go to Microsoft's Website and download the latest patches for them. Microsoft software is notorious for its lack of security.

If your system does get infected, here is how to prevent a virus or worm from sending itself to everyone in your address book: make up a nonsense email address, beginning with _1, such as _1achocolate, and save it in the address book. The underscore and the figure one will put this address at the top of your email address book list. This nonsense address will prevent the virus from sending itself out to anyone else, some experts say.

Increase security in your Internet Explorer browser:

1. Open Internet Explorer.
2. Go to the Tools menu.
3. Select Internet Options.
4. Select the General tab.
5. Select Temporary Internet Files.
6. Select Delete Cookies.
7. Select Delete Files.
8. The system will prompt you to delete all Temporary Internet Files, select Yes.
9. To automate this process for the future, go to the Advanced button under Internet Options; then check the box that says Empty Temporary Internet Files folder when browser is closed.
10. Go to the History section in Internet Options.
11. Select Clear History.
12. Set the number of days to keep pages in history at 7 or 14. You won't need more than that.

Some viruses and worms let third parties use your PC remotely. Here is how to prevent that:

1. Open Internet Explorer offline.
2. Select the Settings button.
3. Select Internet Options.
4. Select the Advanced button.
5. Go to HTTP 1.1 settings and make sure the box for Use HTTP 1.1 through proxy connections is unchecked.
6. Go to the Microsoft VM section and make sure the Java console enabled and Java logging enabled boxes are unchecked.
7. Go to the Security section and check these boxes:
   1. Check for publisher's certificate revocation
   2. Check for server certificate revocation
   3. Use SSL 2.0
   4. Use SSL 3.0
   5. Warn about invalid site certificates
   6. Warn if changing between secure and not secure mode
   7. Warn if forms submittal is being redirected

Turn your PC off. If you are using an always-on connection such as cable or DSL, turn off your PC when you are not using it. Always-on connections have what is called a static IP address, which makes it easy to locate your computer on the Internet and makes it an easy target. Turning off your PC will prevent people from accessing it over the Internet.