It's probably not possible at this juncture. There wouldn't be any drivers for the hardware.

Just wait for about 2 months and Windows 7 will be out. Not saying it will be a magic panacea, but it does refine the Vista interface in a number of small, but useful, ways. In the mean time, you might find you actually like Vista if you give it half a chance. Granted you're stacking the odds pretty heavily against buying an Acer to run it on, but still, why not at least give it an honest chance?

If you're unwilling to do that, then your first step would be to see if you can track down XP drivers for your new system's hardware. If you can, you're in business and there are scores of web pages out there that detail this process, just find one with your search engine of choice. If you can't find XP drivers, then you're dead in the water. You can't necessarily have both a new computer and an aging operating system... One that people leveled pretty much the same complaints at when it was new as people leveled against Vista. Like: it's slow, it's buggy, my programs don't work, there are no drivers for my hardware, etc. Funny how history repeats itself sometimes.