你的本本改XP比较简单, 步骤如下

1. HP OEM XP 光盘
可以从国内网上下.
也可以找个零售版XP, 自己加HP OEMBIOS的四个文件.
使用HP OEM XP的好处是无须激活, 无须输入注册码. 可以自动下微软更新, 无须破解. HP OEM XP的激活过程其实就是读一下BIOS, 找"Hewlett-Packard"这个字符串. 你的本本的BIOS应该已有这个字符串.
如国你已经有正版零售XP, 直接到下一步即可.

2. Slipstream drivers into your XP CD using nLite
The previous post has already listed the steps of the process. It's not that hard.
I already found the chipset/video driver for you.
http://downloadcenter.intel.com/filter_results.aspx?strTypes=all&ProductID=2991&OSFullName=Windows*+XP+Home+Edition&lang=eng&strOSs=45&submit=Go%21

Use winrar to open the exe files and extract the drivers.

Recommendation: Google and see if somebody else has already downgraded to XP and posted the other drivers. HD Audio driver could be tricky to install.

Other thoughts:
Before you do anything, first create the recovery discs in Vista. In case anything goes wrong, you can restore to Vista at least.
Instead of completely removing Vista, you can also set up XP/Vista dual-boot. A good article for XP Vista dual-boot can be found here:
http://apcmag.com/how_to_dual_boot_vista_and_xp_with_vista_installed_first__the_stepbystep_guide.htm

Have fun!