Under Lock and KeyAlways keep your guard up when it comes to computer security.

启动你的生意足够吓人,但thought of a computer security breach could really keep you up at night. Whether you are starting small from a home office or you've procured outside office space, you need to know your security basics. First, take stock of your software. Set up your anti-virus and anti-spyware programs right away. Employ more than one program at all times, especially anti-virus programs, to cover any possible vulnerabilities, says Clint Laskowski, information security consultant at BlueHat Security Inc., an IT consulting company near Milwaukee. Also, back up your data with a simple thumb drive or external USB drive.

Then implement a home network with a NAT router. "It prevents outside people from easily getting into your inside network," says Laskowski. Use an encrypted and password-protected wireless network so others can't steal your bandwidth. Check out some free open source security software atwww.sectools.org,www.clamwin.comandwww.snapfiles.com, or try the beta version ofMicrosoft Windows Defender.

And if you have the budget for it, seek out technology experts to help you get started. Look for a Certified Information Systems Security Professional, or CISSP, atwww.isc2.org, or find a professional with Global Information Assurance Certification atwww.giac.org.

"Security is in the forefront of our mind," says Luke Pilon, 26, co-founder of the Lead Shop Inc., a data company in Solana Beach, California, that provides sales leads to mortgage brokers. Because customer data is the cornerstone of their business, Pilon and co-founders Jordan Glazier, 38, and Paul Ramirez, 48, budgeted $5,000 of their startup capital for security--covering everything from setting up their firewall and e-mail filters to hiring a security company for expertise and additional protection. That peace of mind has enabled them to reach their first-year sales projections of $250,000 for 2006.