As announced last month, Microsoft has now changed its licensing terms for Microsoft Security Essentials, making it available for small businesses on up to 10 PCs. That means small business owners that operate outside of the home will be able to download and install Microsoft Security Essentials legally and for free to protect their computers from malware.

Free antivirus software for home users has been around for a long time, but most free products include similar restrictions to the ones MSE had: using them on corporate desktops is not allowed, unless you pay. Microsoft claims that enterprise security software is too expensive, difficult to set up and maintain for these organizations, hence its decision to expand the reach of MSE beyond the home. For companies that operate a small business with more than 10 PCs, Microsoft still recommends using its Forefront line of security products.

In just one year on the market, MSE is being used by more than 30 million users. The suite has won a lot of praise since its introduction, mainly because it is unobtrusive yet still effective. Do you use MSE, and if not, what do you use?