Microsoft has announced that its free anti-virus software programme, Microsoft Security Essentials, is one year old today, and is celebrating the fact that now over 30 million active users are using the service.

When Microsoft first announced it was creating a free anti-virus service, there wasn't many who thought it would work – given that OneCare was met with a lukewarm reception.

However, Security Essentials has proved to be something of a success, offering free web security but not at the expense of bloating out your computer.

TechRadar spoke to Cliff Evans, MSE product manager, about Security Essentials, who explained that simplicity was the key to making Security Essentials work.

"The philosophy behind MSE was that it would be a pure anti-malware product, so it can run on older machines, netbooks, anything really," Evans explained.

"Performance was important and keeping people secure was important, but we also looked at the UI to make it as simple as possible as we know that people are confused about this subject."

400 million threats

In the whole of last year there were 400 million computer threats which Microsoft had to deal with, removing 366 million of them from people's computers.

This is pretty impressive for a free product and something which must have put the paid-for antivirus publishers' noses out of joint, but Evans is quick to note that there is no bad blood between them and other companies.

"At Microsoft we get a colossal amount of data about malware threats and we publish this data every year in our security intelligence reports.

"It is very much an open shop on the technical side of things. These people [who create anti-virus software] are security researchers, so often we will speak to each other.

"We always get great collaboration in the industry."

Security Essentials on a mobile?

With the rise of smartphones in the market, we asked Evans if there was a phone version of Security Essentials on the way, but he wasn't giving anything away, saying: "We have nothing announced but we continue to look at security effects that will occur on smartphones.

"The range of protection you get with your mobile will increase, but we have nothing to state on this yet."

As for the future of the software, Microsoft is already integrating it into businesses by offering Security Essentials for download and installation on up to 10 PCs from 10 October and it is working with OEMs to sort out ways integrate the product.

The first of these bears fruit soon, with HP Envy laptops shipping to the US with the software pre-installed.

And with IE9 just around the corner, Security Essentials is being pushed as an integral part of Microsoft's computing eco-system.

"We recommend people are using Internet Explorer alongside the antivirus software," explained Evans.

"It works well with the SmartScreen filter – something which has been streamlined in IE9."