There are something wrong with my mbr information. I installed xp on (hd0,0), ubuntu on (hd0,1). Now I can't boot my pc directly from the hardisk. I can only boot it from my flash (u) disk. Because there is a grub for dos on my flash disk, I can use the grub.
Then I can type kernel (hd0,1)/vmlinuz root=/dev/hda2 initrd (hd0,1)/initrd.img boot So that I can boot my pc and entered the ubuntu. But how can I enter the xp? Is it possible?