Use an Internet firewall. An Internet firewall helps screen out hackers, viruses, and worms before they reach your home office computer or network from the Internet.

If you use Windows Vista or Windows XP Service Pack 2 (SP2), you already have a firewall and it is turned on by default. If you don't use these operating systems, learn more about how you can protect your computer.

For more information, see Internet firewalls: Frequently asked questions.
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Update your software. Regular software updates can be crucial to keeping your home office computer or your home office network as secure as possible.

With Microsoft Update you can download critical security software updates for both Windows and Microsoft Office programs, such as Microsoft Word, Microsoft Excel, and Microsoft PowerPoint.
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Use antivirus software. Computer viruses can have serious effects on your business. They can slow down your work, destroy important documents, and more.

You can help protect your home office by using antivirus software and keeping it current. There are many good antivirus programs. Almost any program is better than not having any protection.
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Be careful with e-mail and instant messages (IM). Even if a message appears to come from someone you know, a file attached to an e-mail message or IM could contain a virus, so be sure to contact the sender by some other means to gain added assurance that the attachment is valid.

Also, never reveal personal or financial information in a response to an e-mail request, no matter who appears to have sent it—your home office may be the target of a phishing scam.

To learn more, see Recognize phishing scams and fraudulent e-mails.
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Back up your computer. Create and maintain a backup schedule so that you don't lose important files.

For more information, see How to decide what to back up. For additional tips on backing up for small businesses, see Are you still not backing up your data?
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Use strong passwords and change them often. Strong passwords give you better security against intrusion by hackers and thieves.

To learn how to create strong passwords that you can remember, read Strong passwords: how to create and use them. 
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Don't let children use your business computer without your supervision. Ideally, you should not allow your children to use your home office computer. If your computer needs to serve both your business and family, be sure to supervise your children whenever they use it.

Teach older children not to download programs or open e-mail attachments without your permission, because they might contain spyware or viruses.