1 download ubuntu7.0.4-alternate.i386.iso
2 download vmlinuz initrd.gz from a website of sjtu
3 all put in a root disk, such as e:
4 reboot, and into grub, enter c and go into the command mode
5 find /vmlinuz, the result is (hd0,6)
6 kernel (hd0,6)/vmlinzu root=/dev/ram ramdisk_size=32000 devfs=mount,all
7 initrd (hd0,6)/initrd.gz
8 reboot