1.Download the latest GRUB FOR DOS version.
2.Uncompress to the path C:\, and add c:\grldr="Start Grub" to the bottom of file boot.ini.
3.Download the install image you want from the web.
4.Extract the file "vmlinuz and initrd.img" to the folder boot.
5.Add title Linux Install to the file menu.lst.
kernel (hd0,0)/boot/vmlinuz
initrd (hd0,0)/boot/initrd.img
6.Be care: the disk must be FAT32 which you put the ISO file in.
7.Reboot computer and choose Start Grub, then begin the Linux install, wish you success!