Grub Error 21 after full install to USB hard drive

 

 

 

 

ubuntu 装到移动硬盘上后，不插移动硬盘，GRUB Error 21

 

这是因为装ubuntu引导的时候，把grub装到了移动硬盘上去了。

1。如果本地硬盘上只有Windows 系统

转自

http://www.cnitblog.com/CoffeeCat/archive/2007/10/11/34673.html 

 

使用MBRFix工具进行修复。
MBRFix工具修复MBR很方便，先进入cmd命令窗口，然后进入mbrfix工具所在的目录（用cd命令），然后输入命令 MbrFix /drive 0 fixmbr ，再确认一下即可。重启以后你会发现，没有了Linux，直接可以进入Windows了。

 

使用命令

MbrFix /drive <num> fixmbr                 Update MBR code to W2K/XP/2003

MbrFix 下载地址

http://download.csdn.net/source/398967

 

 

2。如果本地硬盘上还有其他linux 操作系统

 

转自：

http://www.pendrivelinux.com/grub-error-21-after-full-install-to-usb-hard-drive/

 

During the Ubuntu USB hard drive installation process, Grub was accidently moved from the internal hard drive to their external hard drive, rendering the original Linux system unbootable without the external drive plugged in. When attempting to boot from the original Debian Linux system, they would encounter the Grub Error 21 shortly after the Grub 1.5 boot process.

The good news is that the fix to repair Grub on the original system was quite simple and is illustrated below:

Reinstalling or fixing Grub after error 21:

1. Boot into the original Linux system with the external hard drive still installed (or you can boot from a Live Ubuntu CD).
2. Open up a terminal and type sudo su
3. Type fdisk -l and locate your Linux boot partition from the listExample: sda1 or hda1
4. Type grub-install /dev/sdx or grub-install /dev/hdx to reinstall or repair Grub!
5. Reboot and test!

Notes: x represents the drive letter a, b, c, d etc. Replace with your actual drive letter.

sdx= SATA, SCSI or USB devices hdx= IDE devices