Microsoft is still stumbling along. But PC troubles should trip it up eventually, unless new products catch on faster than they are today.

The software giant late Thursday reported results for its fiscal second quarter ended in December. It said sales of the Windows operating system and Office software, Microsoft's two key profit drivers, increased 11% and 3%, respectively, versus the prior year and factoring in deferred revenue. That was despite a 6% fourth-quarter drop in world-wide PC sales, according to IDC.

Microsoft can buck the PC trend a little while since some PC users still need to upgrade soon-to-be-unsupported versions of Windows. But 60% already have moved to the more-recent Windows 7, according to Microsoft, so those upgrades should slow before long.

When that happens, touch-friendly Windows 8, the latest version, has to pick up the slack. But it isn't clear from the latest quarter, the first in which Windows 8 was available, whether it can catch on.

And if Microsoft's new Surface tablet had sold well in what was also its first quarter on the market, the company would likely have disclosed unit sales. It didn't. And a potentially more popular version of the Surface, which is compatible with more apps, won't be released until February.

Meanwhile, Microsoft's oft forgotten but plenty profitable 'server and tools' business didn't perform as well as some had hoped. This segment selling server and other corporate software generates a quarter of revenue and operating profit. It probably should have seen a bigger lift in the December quarter considering the release of new server software.

What's more, Microsoft still looks a long way from grabbing meaningful market share in smartphones. That, plus traction from other new products, would allay fears the company's prospects are soft.