Step 2 - Install XP:
wait while XP installs (I won't go into detail, there are many tutorials on this, and it is reasonably straight forward)
Now that XP has installed, it attempts to boot for the first time... all goes fine, video settings, networking, then the lovely
welcome screen as usual.
You restart, expecting a boot loader screen... followed the tutorial this far, and now you seem to only have XP... well not
quite, I wouldn't leave you hanging without giving you a proper dual boot.
here lies the only real issue with installing XP after Vista, but it's a quick fix if you have your Vista CDs/DVD handy.
The problem is that Vista and XP use different boot loader utilities in the MBR (Master Boot Record) of your hard drive. XP does
not recognize Vista, but Vista will
recognize XP, so we need to remove the boot loader that XP just put in with the old
Vista boot loader. So restart once more, but this time with your Vista disc in the drive.