In a dual boot systems it comes a time when u need to re-install windows ( Yeah, I know ..). When windows finishes copying files for installation and reboots the system it modifies MBR (Master Boot Record). Apparently Mr. Gates believes Windows is the only OS in the whole world. Windows will go on and install a fresh copy windows but with modified MBR now it’s not possible to access the other OS in the system. The situation sucks more for people who uses Linux but don’t know the “How to’” stuffs.

Steps ::

1) Boot with a Linux CD. (Make sure CD/DVD ROM is priority boot device)

2) Open a shell and type
$ sudo grub (It takes you to grub )

3) Now find out the boot stage1 device , so type
$ find /boot/grub/stage1
It ‘ll give you something like …. (hdX,Y) example (hd0,8) [This is where grub 'll go now]

4) Type
$ root (hd0,8)

5) Type
$ setup (hd0,8)

and we are all done

* Just to clear (hd0,8) used here is for reference and example ….. use what you get from find command (step 3)