XP for me!! I bought my first new computer in six years in 2006 just to be sure that I would not have to be saddled with Vista. I had been happily using Win98 but the threat of built-in DRM and the enormous overhead that it requires spurred me into action. The video drivers for video cards have become gigantic - one set of drivers for an nVidia board was as large as the NT 4.0 o/s. It is no wonder that the Vista systems are slow with that kind of overhead. The Vista components are now written in "modules". There are 6 (I think) video modules, of which 4 are concerned with security. The size of the o/s is another problem. There is no way that the o/s code can be grown by a factor of eight without a performance hit. As for the security of the o/s, it is a bit different from XP, so it will take a few months for the hackers to catch up. From my recent reading, all that it means is that rootkits will be written in User mode rather than Kernel mode to circumvent the User Account Management feature. All this wonderfulness is costing us money. When there is a huge coding overhead for Vista drivers, hardware manufacturers will add that to the price of new hardware. In addition, because of the performance hits, we will have to buy better hardware to enjoy the same performance. Add this to the generally user-unfriendly approach of Microsoft - limited installs of the software you have actually paid good money for - activation on only one machine, ever, meaning that if you upgrade your hardware, your o/s may no longer work - and you can count me as a no for Vista, and a vote for XP only because there is not a better choice without having to learn Linux. Every time I think about Vista, I come back to Linux. I may go there yet.