双系统出现问题

[i=s] 本帖最后由 linuxjd 于 2012-8-28 19:15 编辑 [/i]

xp上装ubuntu双系统，开机就出现Ubuntu的安装选项，进去后出现以下这段文字：
(initramfs) /scripts/casper-premount/2-iso_scan: line 46 can't open /dev/sr0： No Medium found
Could not find the ISO/ ubuntu-10.04-dvd-i386.iso This could also happen if the file system is not clean because of an operating system crash, an interrupted boot process, an improper shutdown, or unplugging of a removable device without first unmounting or ejecting it. To fix this, simply reboot into windows, let it fully start, log in run 'chkdsk /r', then gracefully shut down and reboot back into windows. after this you should be able to reboot again and resume the installation.

下grub4dos-0.4.4，解压，把grldr，grldr.mbr，grub.exe 复制到C盘，再将ISO复制到C盘，再把ISO中的vmlinuz，initrd.gz复制到C盘，然后又在C盘创建了
menu.lst
内容为：
title Install Ubuntu
root (hd0,0)
kernel (hd0,0)/vmlinuz boot=casper iso-scan/filename=/ubuntu.iso ro quiet splash locale=zh_CN.UTF-8
initrd (hd0,0)/initrd.lz

boot.ini
内容为：
[boot loader]
[operating systems]
c:\grldr.mbr="ubuntu"

之后重启进入安装界面，可却启示了以上那段错误提示，我应该怎么做呢？
还有网上有人说是不能把ISO放在系统盘，但是教程又能做到，不知是什么原因。麻烦各位帮帮我，谢谢大家！！