Fixing problems of GRUB in ubuntu+win7 dual system

Recently, it was working on the Ubuntu+win7 dual system of Grub boot, using Ubuntu14.04.2. System update, update to the general stuck, just at this time in the Grub related files Update, I put the machine restarted after entering the Grub rescue mode, as follows:

Error:file '/boot/grub/i386-pc/normal.mod ' not found.

Entering Rescue mode ...

Grub Rescue>

After a network search and self-validation, I've summarized three solutions.

1. Make Ubuntu USB boot tool, select the USB stick to boot the machine, enter try Ubuntu, install the Boot-repair tool, use the tool to restore the damaged grub.

A. Install Boot-repair at the command line, first link source address: $sudo add-apt-repository Ppa:yannubuntu/boot-repair

$sudo apt-get Update

$sudo Apt-get Install Boot-repair

B. After the installation is successful, you can start the Boot-repair in dash or in the terminal and start repairing the system.

C. System repair may take a few minutes, after the shutdown unplug the USB flash drive, and then start. You can see the familiar Grub boot interface.

2. Select Normal mode to start directly in Grub Rescue mode, and then modify update grub. The key point of this method is three, one is to choose a good grub partition directory, the second is to find the root of the partition, and three is to have Normal.mod file. The command in this mode is limited, there is a common LS set insmod, through these three commands, to find the above file directory entry set root and prefix, and then select Normal Startup mode.

A.grub rescue>set//This command lists the partition where the boot directory resides, the partition where the grub directory resides;

B.grub rescue>ls//List all partitions, styles such as (HD0,MSDOSX);

C.grub Rescue>ls (HD0,MSDOSX)////list the directories under each partition in order to find root under that partition, where we assume that Grub is in (HD0,MSDOS6)/boot/grub,root (HD0,MSDOS5) on the partition;

D.grub rescue>set root= (HD0,MSDOS5)

Grub Rescue>set prefix= (HD0,MSDOS6)/boot/grub

Grub Rescue>insmod/boot/grub/normal.mod//If you do not have normal.mod this file, select the first or third method.

E.grub rescue>normal//Show Grub Menu

F. After entering the system through the displayed menu, the system is updated and repaired at the command line.

$sudo Update-grub

$sudo GRUB-INSTALL/DEV/SDA//SDA as the hard disk number, not the partition number (SDA1,SDA2, etc.)

$sudo Shutdown-r Now//Restart the machine

PS: You can modify the Grub menu in Grub.cfg.

3. If the first and second methods are not valid, then you can only discard all the things that have never come back, use a good startup tool to re-make an Ubuntu system, and fix grub-_*! in the update.

　

Fixing problems of GRUB in ubuntu+win7 dual system