Windows 8 keeps clawing its way up the market share charts, but not at the expense of Windows 7 or Windows XP.

According to Netmarketshare, Windows 8's market share now stands at 5.4 percent, up 0.3 percent from a month ago when it finally surpassed Windows Vista. Once again, Vista's market share declined last month, this time by about 0.38 percent, to a total of 4.24 percent.

Meanwhile, Windows 7 and Windows XP are holding strong. In fact, Windows 7's market share increased last month by 0.12 percent, and Windows XP saw a 0.02 percent bump in market share despite the looming end of XP support by Microsoft. Both Windows 7 and XP remain the most widely-used operating systems by far, with 44.49 percent and 37.19 percent of the market, respectively, according to Netmarketshare.

In other words, any market share that Windows 8 gained last month appears to be at the expense of Windows Vista.

While it's not surprising that users are eager to upgrade from the widely-panned operating system, getting people to switch from XP or Windows 7 may be tougher for Microsoft, especially among users who want to stick with a traditional desktop interface.

Windows 8.1 will make some concessions for those users, with the return of the Start button, a boot-to-desktop option, quicker access to advanced desktop functions, and a way to prevent modern-style menus from popping up during desktop use.

But ultimately, Microsoft and PC makers must convince the masses that they need to upgrade their hardware to touch-enabled laptops, hybrids, or desktops. Cheaper touchscreen devices could help on that front, but it'll likely be a while before the market share needle moves much for Windows XP and Windows 7.