Can't resize partitions! Through Knoppix or fedora!

[maseAT]

Hi, I have one hard disk right now, running Fedora core 4. it has two partitions, sda1 and sda2, which is the boot partition and the drive. So i want to resize the second one so that I can install windows xp on my computer. when i run qtparted as root from fedora, the resize option when right-clicking is grayed out. so i booted to knoppix liveCD and ran qtparted as root, and same thing. i even changed the hard disks to writeable. what is the deal here? i've tried unmounting the drives from knoppix, but it says they're not mounted! any help please!