Assuming that you are installing
Windows 7 on a separate partition in a
machine that had Windows XP and Linux
installed already.
If your machine had only Windows XP
and no Linux, Windows 7 is generous
enough to let you choose to boot older
version of Windows through its boot
manager.
But, it deliberately ignore other
non-windows OS and file system, and
hence you can’t boot Linux through
Windows 7 boot manager.
In such case, you need to restore GRUB
boot manager. Follow these steps
carefully and restore your old GRUB:
Boot through Ubuntu Linux Live CD/DVD
Start terminal and give following
command:
$ sudo grub
You will then enter in grub
configuration mode. Here, give
following command:
$ root (hd0,0)
Then give following command:
$ setup (hd%1,%2) - here, %1,%2 is the
disk volume and partition value of
your original Linux installation where
/boot/grub is already installed. For
example, in my machine, it is on disk
1, partition 6, so the value will be –
(hd0,5). So, be careful here else your
Grub will not be restored, and you
will get error message instead.
Finally, give following command within
grub configuration mode:
$ quit
$ exit
Now, reboot (do not forget to remove
Linux Live CD/DVD to boot from HDD).
If everything had gone right, your
Grub boot manager will load and prompt
you to choose to boot from either
Linux or Windows 7. Enjoy!
Best Answer
I think Google may have got you this answer quicker :)
Boot from the Windows 7 CD/DVD you have and choose the repair option when asked. No problems will be found, but when asked select 'command prompt' and then enter the following
Give your machine a reboot and hey presto, you're back to booting straight into Windows without GRUB.