If you want to allow faster booting by having Windows XP, enable boot defrag. This will put all of the boot files together on the hard drive for faster access. To do this:

1. Go to "Start-->Run" and enter "Regedit" in the box. Hit OK.
2. Navigate to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Dfrg\BootOptimizerFunction.
3. Select "Enable" from the list on the right.
4. Right click on it and select "Modify"
5. Change the value in the box to "Y" to enable it; "N" of course means it's disabled.
6. Reboot the computer and you're all set.