W hen you configure a computer to dual boot between Linux and Windows, we must remember that Windows is installed first, because, while Linux from what democratic system recognizes the presence of another OS, but it beats Windows and overwrites the 'MBR, making it impossible to choose dell'alltro os. If this happens, everything can be solved using a live CD. Once booted from the live CD, we mount the partition on which you installed Linux. If you do not know what it is, use:

fdisk-l

then montiamola with

mount-t ext3 / dev/hda1 / mnt

clearly replace hda1 with its corresponding partition. If you had a separate partition for / boot, you must also install the

mkdir / mnt / boot mount-t ext3 / dev/hda2 / mnt / boot

even the file system mount / dev and proc

mount-bind / dev / / mnt / dev mount-t proc proc / mnt / proc

now we chrooted

chroot / mnt

then we go into Grub and we give the following commands

grub root (hd0, 1) setup (hd0) quit

where hd0, 1 and hd0 refers to the first partition of first disk. To avoid this procedure may make up the 'MBR, follow these steps. Another very useful tool, is to use Super Grub Disk, and as a downloadable floppy image, both as cd-rom.

A ll we know what 's MBR (master boot record), and all of us especially in the beginning we feared, above all, when you install the kind of OS, which will cost much, and does not give you anything, not even a program , no, there is one, notepad.exe. However, as we all know, in 'MBR boot loader is installed and closed the partition table. So if you sminchiasse for us would be a waste of time, and also un'incazzatura. So since prevention is better than cure, our help comes towards the dd command, which saves us the first 512 bytes of disk.

# Dd if = / dev / sda of = ~ / mbr.img bs = 512 count = 1

Et voila. Now it is safe. Check the content we use:

od-xa mbr.img

To restore use:

mbr.img dd if = of = / dev / sda bs = 512 count = 1