You've been raising some big questions in the forums about 64-bit. Here's our FAQ to 64-bit Vista vs XP, and whether it's worth the hassle if you're not a workstation user, but a gamer or power user. Which is better: 64-bit Vista or 64-bit XP?
In terms of hardware support there is no question: support for 64-bit Vista far outstrips 64-bit XP. We’re not going to argue aesthetics or interface here, but if you want to be sure of running new hardware on your 64-bit system, Vista is really your only choice. Fewer and fewer vendors are going to release drivers for 64-bit XP, and many didn’t even bother in the first place. 64-bit Vista support, however, while still lagging behind 32-bit, is gradually making its way towards universal.

In a blog post this week, Microsoft's Chris Flores noted that 20 percent of new Windows Vista PCs in the U.S. that connected to Windows Update in June were running a 64-bit version of the OS, compared with 3 percent of new computers in March. "Put more simply, usage of 64-bit Windows Vista is growing much more rapidly than 32-bit," he said. "Based on current trends, this growth will accelerate as the retail channel shifts to supplying a rapidly increasing assortment of 64-bit desktops and laptops."

"We've determined this problem occurs on AMD-based machines with Windows XP images that were originally captured by an OEM on an Intel-based machine," said Microsoft in an anonymous post to its Micrososft Update team's blog . "The problem is a registry value, present on images created with Intel processors, that causes a driver (intelppm.sys) to load at boot. When intelppm.sys attempts to load on an AMD-based system upon the install of SP3, it causes a blue screen and the continuous reboot."

According to Johansson, there appears to be two separate problems. One affects only AMD-equipped PCs sold by Hewlett-Packard. "The problem is that HP, apparently along with other OEMs, deploys the same image to Intel-based computers that they do to AMD-based computers," said Johansson. "Because the image for both Intel and AMD is the same all have the intelppm.sys driver installed and running. That driver provides power management on Intel-based computers. On an AMD-based computer, amdk8.sys provides the same functionality. "