USB

Windows XP natiebvly supports USB 1.1 and 2.0. Third party drivers can enable later versions.

Booting from USB
The default disc only supports booting from an optical medium but third party installers and tools like easy2boot support usb booting. Many older bioses may not support usb booting so may need a bios update or disc drive.

Warning
Don't use a SATA-to-USB adaptor. It will screw up on step 2.