Hey, what is going on here? In Thursday's list of Amazon's best-selling portable computers, only seven out of the top 25 run Windows! As you might expect, Apple takes a lot of the spots, but it's not just MacBooks. The Linux-based Asus Eee PCs and Nokia tablets are grabbing high positions in the list. That's a lot of computers that aren't paying tribute to Microsoft.Let's come back to earth for a moment, though. Direct vendors like Dell, and sales through corporate channels, aren't represented in Amazon's ranking. The recent market share data shows that although Apple's share of the market is growing faster than any other manufacturer, Microsoft OEMs rule the roost. Still, it's a thing that makes you go, "Hmmm." There are some disturbing signs here.

The e-mails revealed as part of the "Vista Capable" lawsuit showed that the strength of the low-end notebook market took Microsoft by surprise. At the same time Vista was driving hardware requirements higher, users were falling in love with inexpensive notebooks like the $300 Asus Eee PC. To make matters worse, 2007 was the turning point where for the first time more than half the PCs sold were portable models. Vista's hardware needs were growing at the same time the hardware was shrinking.

Small and cheap isn't the only appeal, though. Apple's notebooks are far from inexpensive, but they seem elegant and better engineered. Apple's unit sales have the highest rate of growth, despite their higher prices. It's getting a lot easier to switch to Macs without going cold-turkey on Windows, thanks to virtual machine software like Parallels. I even know a Windows developer who bought a MacBook Air and is running his Windows development tools and test environments in Windows VMs. For the short term, it's no skin off Microsoft's back if users run a Mac but still buy Windows licenses to run the software they can't get on a Mac. Long term, though, those users will migrate to Mac apps and Microsoft could find itself out in the cold.

Design is where nearly all Microsoft's OEMs show their weaknesses. A typical Windows notebook PC is nowhere near as "sexy" as an Apple one, and most OEMs compound the problem by saturating the computer with crapware that ruins the whole experience right out of the box. As much as people like to blame Microsoft for the problems of Windows PCs, OEMs control the overall experience and they often do a bad job. If Windows suffers a downturn, the OEMs will need to share the blame with Microsoft.