1. 下載UBUNUT 12.04系統，並製作成U盤啟動

2. U盤啟動UBUNTU，並選擇 體驗UBUNTU 模式進入UNTUNTU 安裝介面

3. 開啟軟體商店，全屏後，在左上解頂部選擇選單裡設定軟體源，選擇為自動搜尋最佳軟體源模式。

4.下載安裝boot-repair軟體，進行修復:

以下內容來自:https://help.ubuntu.com/community/Boot-Repair

Boot-Repair is a simple tool to repair frequent boot issues you may encounter in Ubuntu like when you can't boot Ubuntu after installing Windows or another Linux distribution, or when you can't boot Windows after installing Ubuntu, or when GRUB is not displayed anymore, some upgrade breaks GRUB, etc.

Boot-Repair lets you fix these issues with a simple click, which (generally reinstalls GRUB and) restores access to the operating systems you had installed before the issue.

Boot-Repair also has advanced options to back up table partitions, back up bootsectors, create aBoot-Info (to get help by email or forum), or change the default repair parameters: configure GRUB, add kernel options (acpi=off ...), purge GRUB, change the default OS, restore a Windows-compatible MBR, repair a broken filesystem, specify the disk where GRUB should be installed, etc.

Boot-Repair is a free software, licensed under GNU-GPL. Boot-Repair should besoon included in Ubuntu official repositories, until then use it at your own risk.

Getting Boot-Repair

1st option : get a CD including Boot-Repair

The easiest way to use Boot-Repair is to burn one of the following disks and boot on it.

• Boot-Repair-Disk is a CD starting Boot-Repair automatically.

• Boot-Repair is also included in Linux-Secure-Remix.

2nd option : install Boot-Repair in Ubuntu

- choose "Try Ubuntu"

- connect to the Internet

- open a new Terminal, then type:

sudo add-apt-repository ppa:yannubuntu/boot-repair && sudo apt-get update

- Press ENTER.

- Then type:

sudo apt-get install -y boot-repair && (boot-repair &)

- Press ENTER

Using Boot-Repair

Recommended repair

• launch Boot-Repair from either :
  • the Dash (the Ubuntu logo at the top-left of the screen)

  • or System->Administration->Boot-Repair menu (Ubuntu 10.04 only)

  • or by typing 'boot-repair' in a terminal

• Then click the "Recommended repair" button. When repair is finished, note the URL (paste.ubuntu.com/XXXXX) that appeared on a paper, then reboot and check if you recovered access to your OSs.

• If the repair did not succeed, indicate the URL to people who help you by email or forum.

Advanced options

Warning: the default settings are the ones used by the "Recommended Repair". Changing them may worsen your problem. Don't modify them before creating aBootInfo URL, and asking advice onthis thread.

5.出現由於原來的UNUNTU系統由於代理而不能上網更新檔案時:

進行如下操作:

rm /mnt/boot-sv/sda5//etc/apt/apt.conf                  #/etc/apt/apt.conf 為原系統根目錄下的/etc/apt/apt.conf,記錄代理地址