The evolution of Windows in parallel with computing architectures can be mapped out in accordance to the following marks: 32-bit, 64-bit, 128-bit and even further along. But while milestones have the potential to offer a consistent growth in terms of performance, they also come with inherent setbacks when it comes down to compatibility. According to Christopher Flores, Director Windows Communications, over the past three months Microsoft has noticed an increasing trend in the adoption of 64-bit editions of Windows Vista to outpace the 32-bit variant of the Windows operating system.

The translation is simple. The Windows client is at a juncture, a point marked by the transition from x86 to x64. And 64-bit Windows is starting to become mainstream with 32-bit versions of the platform beginning to fade into the background. This scenario is possible mainly through the new direction adopted by Original Equipment Manufacturers. While end users have failed to crowd to the new 64-bit technologies and software by themselves, OEMs are offering the necessary catalyst, by adjusting their offerings to reflect the fact that x64 is the future.

"This change begs a few questions: is the 64 bit market ready to go mainstream? Will consumers realize the benefits from larger chips and 4GB or more of memory? The answer to both of these questions is yes - but a qualified yes. Preconfigured 64-bit PCs obtained from retailers or PC manufacturers should work quite well. This is in stark contrast to the experience of many technology enthusiasts who built their 64-bit PC from scratch and may have had to scour the Web looking for drivers. So, unless you really love to tinker with your PC, we suggest you buy a pre-built 64-bit PC at retail or directly from a PC manufacturer," Flores stated.

64-bit CPUs and Windows platforms do offer enhanced performance and the possibility to go well beyond the 4 GB RAM limitation of 32-bit Windows (the high end editions of x64 Vista support up to 128 GB of system memory). But they also bring to the table incompatibility issues related mainly to drivers, but also to software.

"In the future, we expect both compatibility and performance of 64-bit PCs to continue to improve. Most hardware devices have 64-bit drivers today and most software products work unmodified because of the 32-bit emulation technology in 64-bit Windows Vista (called WOW64). But there are some gaps, especially in the long tail of the market, but we expect rapid improvement now that 64-bit PCs are getting so popular. Over time we'll see more 64-bit-optimized programs hit the market, which promise dramatic performance and experience improvements," Flores added.

Both Flores and technology Evangelist Keith Combs, pointed to the Windows Vista Compatibility Center as a resource for end users to check whether a certain application is compatible with 64-bit Windows. Alternatively, the presence of the Works with Windows Vista or Certified for Windows Vista logos is a guarantee that the hardware and software products are compatible with both 32-bit and 64-bit Windows Vista editions. Since this is still the transition from x86 to x64, 128-bit Windows is not even on the horizon, as the 64-bit version of the Windows client is yet to actually become mainstream. Still, the soil seems fertile for 32-bit to be left behind, and Microsoft Evangelist Neil Hutson welcomed the idea.

"I think that this is great news for the industry. This gives the OS more space to breathe (in 32-bit it is always competing with Apps for Memory and processor) and will give consumers and application developer writers more opportunities to build and use a new generation applications running on the client which can use this new capability. Finally the feedback that I am getting from the external community about 64-bit Vista is really encouraging; they love it and would not go back. Let's hope the trend continues. And no I will not be evangelizing 128bit!!!" Hutson stated.