Installing Windows After Ubuntu

Normally when Windows is installed after Ubuntu the master boot record will be overwritten. This means that you would have to boot off a LiveCD and re-install grub. The steps are

#sudo grub

From the grub

Type

grub> find /boot/grub/stage1 (If you installed separate /boot partition, then find /grub/stage1 )

(hd0,1)

(hd0,5)

It dispay partition which contains your grub files. I have two linux OS installed.

Then run the following command

>root (hd0,1)
>setup (hd0)

(hd0) = the MBR for the hard disk which is where grub needs to install itself too for it to load on bootup.

Another Method

fdisk -l

Disk /dev/hda: 120.0 GB, 120034123776 bytes
255 heads, 63 sectors/track, 14593 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Device Boot      Start         End      Blocks   Id  System
/dev/sda1               1           8       64228+  83  Linux
/dev/sda2               9        1224     9767520   83  Linux
/dev/sda3   *        1225        2440     9767520   a5  FreeBSD
/dev/sda4            2441       14593    97618972+   5  Extended
/dev/sda5           14532       14593      498015   82  Linux swap / Solaris
/dev/sda6            2441       14530    97112862   83  Linux

Partition table entries are not in disk order

Here are listed three Linux partitions. /dev/sda2 is the root partition, /dev/sda1 is the /boot partition and /dev/sda6 is the /home partition. If you only have one partition, this means that your entire Ubuntu system is installed on that one.

Later there will be a section on how to determine which partition your Ubuntu installation is on if you have several different partitions.

First, create a mountpoint for your partition, for example:

mkdir /media/root

Then mount your partition in it. If you don’t know which one it is, then mount any of them, we will determine if it is the correct one.

mount /dev/sda2 /media/root

Replace /dev/sda2 with the correct name of your partition. To check if it is the correct one, run ls /media/root which should output something like this:

bin    dev      home        lib    mnt   root     srv  usr
boot   etc      initrd      lib64  opt   sbin     sys  var
cdrom  initrd.img  media  proc  selinux  tmp  vmlinuz

If what you have looks nothing like this, the drive you have selected is incorrect. Run umount /media/root in the Terminal to unmount it then mount and try another one. Should you have made a /boot partition you can mount it like so:

mount /dev/sda1 /media/root/boot

To make sure this is indeed the /boot partition, run ls /media/root/boot, which should output something like this :

config-2.6.18-3-686      initrd.img-2.6.18-3-686.bak  System.map-2.6.18-3-686
grub                     lost+found                   vmlinuz-2.6.18-3-686
initrd.img-2.6.18-3-686  memtest86+.bin

Once again, if what you have is not similar, unmount it and try another partition.

Now that everything is mounted, we just need to reinstall GRUB:

sudo grub-install –root-directory=/media/root /dev/sda

If you get BIOS warnings try:

sudo grub-install –root-directory=/media/root /dev/sda –recheck

Note: Replace /dev/sda with the location you want to install GRUB on. If all went well, you should see something like this:

Installation finished. No error reported.
This is the contents of the device map /boot/grub/device.map.
Check if this is correct or not. If any of the lines is incorrect,
fix it and re-run the script `grub-install’.

(hd0)   /dev/sda

Reboot, making sure to boot to your hard drive and not to the live CD. Grub should be installed and both Ubuntu and Windows should have been automatically detected.