In a busy startup environment, computer security can sometimes become an afterthought, but now there’s no excuse for not protecting your machines and your network. Starting in October, Microsoft’s widely lauded Security Essentials software will be available for free to small businesses.

Under the current license, Microsoft’s streamlined no-nonsense anti-virus and anti-spyware suite for Windows is available free to home users only. Next month small business owners will be able to install Security Essentials on up to 10 PCs.

There are plenty of other computer security suites out there, some more powerful, and some with more features, but when you’re on a startup’s budget, it’s hard to argue with free.

It may only be a licensing change, and I suppose the software suite could theoretically be used on business machines right now, but we know our readers would never violate a software licensing agreement.