Install Linux from Hard Disk on Windows7

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Centos 5.5
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Windows7 is install on C:.

First download grub4dos. I have used 0.4.4. Extract grub4dos-0.4.4.zip and copy
grldr, grldr.mbr and grub.exe to C:.

Download CentOS-5.5-i386-bin-DVD.iso. Find vmlinuz and initrd.img in isolinux
folder and copy them to C:.

Create menu.lst file in C:.

color black/cyan yellow/cyan
timeout 30
default /default
title Microsoft Windows 7
root (hd0,1)
savedefault
makeactive
chainloader +1
title Install CentOS 5.5
root (hd0,1)
kernel (hd0,1)/vmlinuz
initrd (hd0,1)/initrd.img


hd0.1 denotes the first partition in the first hard disk. Since Windows7 creates
100M partition before windows7 system partion. hd0.1 is used. If there is not
such a 100M partion, hd0.0 should be used.

-----------------------------------
| 100M | windows7 partion | other |
-----------------------------------

Open a command line with admistrator rights. Type

bcdedit /create /d "GRUB4DOS" /application bootsector

Copy the GUID. The GUI is used in the following three commands.

bcdedit /set {GUID} device partition=C:
bcdedit /set {GUID} path \grldr.mbr
bcdedit /displayorder {GUID} /addlast

Copy CentOS-5.5-i386-bin.iso to the root folder of a FAT32 partition. In my
case, it is D:. I don't know whether NTFS works and whether the iso can be placed in
a folder other than the root.

Reboot machine. Choose GRUB4DOS. Then chose Install CentOS 5.5. Choose Hard Disk
when be asking for installation media (The installation also recognized
partitions on a USB hard disk).  Then choose the partion which contains the iso. 
In my case, it is /dev/sda5. 
http://wenku.baidu.com/view/222ae33383c4bb4cf7ecd180.html is a good explanation
of the mapping between Windows partition naming and linux partition naming. 
Input / as the folder which contains the iso. After doing this, the following
steps are similar
to the installation from CD/DVD. During the installation, just make sure that
window7 installation are recognized by linux GRUB.

During the installtion,
http://blog.csdn.net/crystony/archive/2010/05/21/5613586.aspx helps me a lot. 
Thanks to the author.

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Ubuntu
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Copy ubuntu-10.04-desktop-i386.iso to C:.

memu.list

color black/cyan yellow/cyan
timeout 30
default /default
title Microsoft Windows 7
root (hd0,1)
savedefault
makeactive
chainloader +1
title Install Ubuntu
root (hd0,1)
kernel (hd0,1)/vmlinuz boot=casper iso-scan/filename=/ubuntu-10.04-desktop-i386.iso ro quiet splash
initrd (hd0,1)/initrd.lz

Everything else is similar to the installation of Centos 5.5.