WHY ALL PREFER MICROSOFT'S WINDOWS XP OVER WINDOWS VISTA?  

I feel xp is preferred over vista by most users as windows xp uses less RAM than vista. Windows xp can easily run smoothly on 256 mb ram whereas windows vista requires 512 mb ram for smooth running. The only thing good about vista is that it has got a more stylish look and features like firewall and internet explorer,media player have been updated. You can just have vista transformation pack to make your windows xp look like vista.

I don't prefer it, I'm just waiting to make sure everything is going with vista before purchasing it.

i think because xp are stable OS and very friendly to use
vista need strong computer and not all pepole have strong
computer

have a nice day

I think many people also waiting for the results of the vista that tested by world, we allready know that microsoft product always identiq with patchs and bugs expecially when it first relase, wait for the next service pack would be better than use your own system as a trial, expecially when you care about your system stability.
maybe like that.

Windows Vista clearly is not a great new performer when it comes to executing single applications at maximum speed. Although we only looked at the 32-bit version of Windows Vista Enterprise, we do not expect the 64-bit edition to be faster (at least not with 32-bit applications).

Overall, applications performed as expected, or executed slightly slower than under Windows XP. The synthetic benchmarks such as Everest, PCMark05 or Sandra 2007 show that differences are non-existent on a component level. We also found some programs that refused to work, and others that seem to cause problems at first but eventually ran properly. In any case, we recommend watching for Vista-related software upgrades from your software vendors.

There are some programs that showed deeply disappointing performance. Unreal Tournament 2004 and the professional graphics benchmarking suite SPECviewperf 9.03 suffered heavily from the lack of support for the OpenGL graphics library under Windows Vista. This is something we expected, and we clearly advise against replacing Windows XP with Windows Vista if you need to run professional graphics applications. Both ATI and Nvidia will offer OpenGL support in upcoming driver releases, but it remains to be seen if and how other graphics vendors or Microsoft may offer it.

We are disappointed that CPU-intensive applications such as video transcoding with XviD (DVD to XviD MPEG4) or the MainConcept H.264 Encoder performed 18% to nearly 24% slower in our standard benchmark scenarios. Both benchmarks finished much quicker under Windows XP. There aren't newer versions available, and we don't see immediate solutions to this issue.

There is good news as well: we did not find evidence that Windows Vista's new and fancy AeroGlass interface consumes more energy than Windows XP's 2D desktop. Although our measurements indicate a 1 W increase in power draw at the plug, this is too little of a difference to draw any conclusions. Obviously, the requirements for displaying all elements in 3D, rotating and moving them aren't enough to heat up graphics processors. This might also be a result of Windows Vista's more advanced implementation of ACPI 2.0 (and parts of 3.0), which allows the control of power of system components separately.

Our hopes that Vista might be able to speed up applications are gone. First tests with 64-bit editions result in numbers similar to our 32-bit results, and we believe it's safe to say that users looking for more raw performance will be disappointed with Vista. Vista is the better Windows, because it behaves better, because it looks better and because it feels better. But it cannot perform better than Windows XP. Is this a K.O. for Windows Vista in the enthusiast space?

If you really need your PC to finish huge encoding, transcoding or rendering workloads within a defined time frame, yes, it is. Don't do it; stay with XP. But as long as you don't need to finish workloads in record time, we believe it makes sense to consider these three bullet points:

* Vista runs considerably more services and thus has to spend somewhat more resources on itself. Indexing, connectivity and usability don't come for free.
* There is a lot of CPU performance available today! We've got really fast dual core processors, and even faster quad cores will hit the market by the middle of the year. Even though you will lose application performance by upgrading to Vista, today's hardware is much faster than yesterday's, and tomorrow's processors will clearly leap even further ahead.
* No new Windows release has been able to offer more application performance than its predecessor.

Although application performance has had this drawback, the new Windows Vista performance features SuperFetch and ReadyDrive help to make Vista feel faster and smoother than Windows XP.