Triple Boot Windows 7 / Windows XP / Ubuntu

Many of us want to use more than one OS on laptop or PC. 

One option here is to use some Vmware, Virtualbox or some other software like this. These softwares runs other OS on top of the current running OS, like you can run Ubuntu on Windows 7, but do not get some functionality with this option. Now if you do not want to do this, other option is to install other OS along with the current OS, so when you start your machine you can OS to boot from. So here are the steps if you want to install three OS (Windows XP, Windows 7 and Ubuntu). You can use this method to make your system dual boot, too.

1. Fresh installation of all OS :

First of all if you are planning to perform fresh installation of three OS, create partitions for each OS depending on your requirement. For example if you want to use windows 7 as a primary OS ans XP to run C, and other programs like that just create a 5 GB partition for it.

For partitioning you can use some software or windows 7 in built utility.

After creating partitions first install XP and then install windows 7. Once done on booting you will get option to select either XP or Windows 7. Remember the order as installing in reverse order i.e. windows 7 and the XP will cause system to boot only in XP.

Now simply install ubuntu. Ubuntu's bootloader (GRUB/GRUB 2.0) will automatically detect the other os and add it to boot menu.

Now if you have done all steps correctly you will see a  grub boot menu with few options like boot ubuntu, ubuntu recovery mode and windows 7 loader and may be someother, too. If you select the windows 7 loader you will get option to select between XP and Windows 7.

same method is applicable if you have installed XP, or XP and windows 7, just install remaining OS.

2. You have windows 7 insta-lled :

If you already have windows 7 installed then first install windows XP. Now after you reboot you will be able to boot only XP. Now insert the windows 7 CD or boot from windows 7 USB, from the windows 7 menu select repair and select startup repair. Now you will reboot windows 7 will start. Now open cmd as administrator and type

bcdedit  /create  {ntldr} /d  "Microsoft Windows XP"
bcdedit  /set  {ntldr}  device partition=X:
bcdedit  /set  {ntldr} path  \ ntldr
bcdedit  /displayorder  {ntldr} /addlast

where X is the drive you have installed windows 7.
Then simply install Ubuntu.

Same is applicable if you have installed windows 7 and Ubuntu installed, you just have to one additional thing, grub repair which explained is in below section.

3. You have XP/Windows 7 and Ubuntu installed :

So if you have Ubuntu already installed. Now If you have XP along with it then simply install windows 7 and the do the grub repair. If you have windows 7 with ubuntu then follow the steps of section 2 and then repair the grub.

To repair the grub follow these steps :
Insert the ubuntu livecd or USB and boot from it. Select try Ubuntu without without installing. It will open the desktop environment for you. Open terminal (alt+ T) and type following commands.

sudo fdisk -l

this will give you the list of the patitions on your disk. note the name (/dev/sdx) where system is Linux.

now type

sudo  grub-install /dev/xxx

where xxx is your linux patition.

Then reboot and you would see the grub menu.

Or you can also use boot-repair.