This setup works very well for an inexpensive XP/Feisty duel boot with no repartitioning risk:
Celeron D Processor
512 MG RAM
two Western Digital 80 Gig Hard drives.
Embarq 100Mb/s Ethernet box, E100 driver.
Starting with a normal XP-box, make existing XP-drive Slave, install new blank drive as Master. Install Ubuntu to Master drive, GRUB will load with Ubuntu, no changes made to XP drive. A useful setup for a desktop that requires XP for work. No risk to Windows files.