From reading these replies, it is very clear to me that some of the respondents have never done this before, and as a result are giving bad, or flat out incorrect advice.
THeZohan says:
"download the drivers for your sata and when you go to load XP hit F6 and put the disc in and viola!"
and
"you can use a thumb drive or burn to a CD .. "
Unfortunately, this is all wrong.
Windows XP will ONLY accept SATA drivers during installation from either a Floppy Disk (that's what you get by pressing F6 at installation time), or if they are slipstreamed into the installation disc itself. Period. On a computer that's about 3 years old or newer, you can use a USB floppy disk drive with the SATA drivers on the floppy disk. Basically, if you can boot a DOS boot floppy from a USB floppy drive, then XP will be able to read SATA drivers from it. Otherwise, it won't.
Vista has a lot of shortcomings, but one area is has XP beat is that it can scan all media types for SATA (and other) drivers, ranging from floppies, CDs/DVDs, thumbdrives, and even other hard drive partitions.
Ghosth writes:
"Much easier if you can install the XP side first, then after its up and stable install or reinstall vista."
Not true. Installing XP after installing Vista takes one or two extra steps. It is easy.
The problem here is that XP's bootloader doesn't know anything about Vista, so after you partition the hard drive and install XP, there's no way to select the Vista partition at boot time.
To fix this, just boot into XP and download and install VistaBootPro. It will restore Vista's boot menu and add XP to it in about 3 seconds. VistaBootPro used to be free and is now $10, but the free version is still floating around, such as here:
http://freeloaded.net/vistabootpro-320/Full instructions are here:
http://www.howtogeek.com/howto/windows-vista/install-windows-xp-on-your-pre-installed-windows-vista-computer/Finally, to get SATA drivers, I would suggest the the following:
In Vista, run HWiNFO32, downloadable from
http://www.hwinfo.com/ and it should tell you exactly what hardware and chipsets you've got in that thing. Then start googling and downloading them from sources other than Gateway, since they provide next to nothing.
Good luck, and let us know how it turns out.
-Llama