Anyone who thinks PC gaming is in trouble hasn’t heard of Steam.

Valve’s popular PC game store and online service now has more than 65 million active accounts, the company announced, up 30 percent from a year ago. The number of PC gamers using Steam is now greater than the number of Xbox Live users, which stands at 48 million according to Microsoft.

Unmentioned by Valve, however, is how many of those users are on Windows, versus other platforms. It’s probably the vast majority.

Valve has a big challenge ahead as it tries to make Linux the premiere gaming platform of the future. The company is preparing to launch SteamOS, a Linux-based open platform for living room gaming, and has promised a variety of “ Steam Machines” to come.

With 65 million active users, Valve is trying to capitalize and expand into TV game consoles. The problem is that most of the 3,000 games on Valve’s Steam service are Windows-only, and it’s unclear how willing publishers are to port their games to Linux.

Valve head Gabe Newell has been quite vocal in his disdain for Windows 8’s walled app store, but for now, Valve plans to use Windows as a crutch, offering in-home streaming to Steam Machines from networked PCs.

At the same time, Valve’s huge number of users shows how much of an opportunity Microsoft has (or has missed) to expand Xbox gaming beyond consoles. Although some games are available under the Xbox banner for Windows 8 and Windows Phone, most of them are casual titles with little appeal to the millions of core gamers who now rely on Steam. Microsoft’s efforts over the years to offer a proper PC gaming platform have fallen flat, and the company recently shuttered its Games for Windows Live Marketplace .

Microsoft bouncing back?

However, Microsoft seems to be regrouping. In August, the company hired Jason Holtman, who formerly led Valve’s downloadable games business. Holtman confirmed that he’ll be working on Windows gaming, though his exact role is unknown.

After Microsoft closed Games for Windows Live Marketplace, the company provided a statement to IGN: “We believe in Windows/PC gaming and have long-term plans to grow our support. We expect there to be transitions as we build out new investments, but we remain committed to bringing first party gaming services and games to Windows for years to come.”

It’s a vague statement, but commitment to PC gaming now seems vital with Valve touting more users than Microsoft has on Xbox Live. The sheer quantity is either too big of an opportunity for Microsoft to pass up, or too much of a threat to ignore.

This story, "Steam user count tops Xbox Live ahead of Valve's console push" was originally published by TechHive .