Microsoft needs Windows 8 to be a hit. Steve Ballmer’s job may even depend on it. That’s why the company is going all out to get consumers on board with buying a PC, or a Windows 8 equipped tablet. Adoption is still growing, but it’s looking like it might not be growing fast enough.

Kitguru compared launch data from Net Applications for Windows 7, Windows Vista and Windows 8. The picture it paints isn’t pretty as Windows 8, which was actually doing better than Vista, is now starting to fall behind in adoption. It’s a far cry from Windows 7 which was a great success for Microsoft at launch, and finally took over Windows XP’s longheld position as the most popular OS in September of last year.

It’s strange to see adoption slowing down after Microsoft announced only a month after its launch that Windows 8 had already sold through 40 million licenses.It seemed like the company’s momentum would continue into the new year, but that may no longer be the case. Many people have expressed displeasure with the touch-oriented operating system and are sticking with Windows 7 until something better comes out.

That something better may just reveal itself to be Windows Blue, the rumored operating system from Microsoft that will reportedly launch later this year. The rumors point to Microsoft moving to an annual release cycle, much like OS X, and the price of the operating system would dramatically decrease to increase adoption. If they’re smart, the Windows team at Microsoft would also implement more desktop friendly controls into this next iteration of Windows 8 to address many of the complaints enthusiast users have with the OS.

It was unlikely that Windows 8 would outpace Windows 7, but it’s still too early to deem the new OS a failure. It may have hit a snag for now, but adoption rates could increase in 2013 to at least make it more popular than the mostly universally reviled Vista. It might even be considered a success at Microsoft if it can at least do that.