If you have a GPT partition and UEFI is turned on in Bios (no matter whether the boot mode you choose is Legacy+UEFI or UEFI, UEFI is considered turned on), then you can ignore this article when installing Ubuntu and just read the installation tutorial at the end.
- Problems that will occur when the following 2 problems are superimposed
引导丢失(versions Ubuntu20.xx, Ubuntu22.xx)
Question 1: The existing system uses MBR partitioning (many people install Win7 in MBR partition mode, and many Win10 also use it)
Question 2: UEFI is turned on in Bios
Generally, old machines use the MBR partition mode to install Win7 or Win10, while new machines use the GPT partition mode by default. If you are installing a second system on the old computer (you already have Win10 and want to install Ubuntu or other Linux) I am running a dual system, but after installing Ubuntu, I cannot find the Win startup item, nor can I find Ubuntu. There is no system available at this time. The purpose of this article is to prevent such 引导丢失problems. What? Already had a problem? Don’t worry, we also have a solution:
grub-install/dev/sda failed1. The solution appears at the end of installing Ubuntu and cannot see the boot entry when restarting the computer.
1. Boot into the motherboard Bios, set to [Legacy+UEFI] mode, and turn off the UEFI mode of the U disk in the system startup item, save and exit 2. Insert the boot disk, select, repair
grub 试用Ubuntu, then unplug the U disk and try again Restart and you will see the startup items. Or not? See the third step 3 below
. If the second step fails, you can try [use Legacy+UEFI mode for the motherboard and set the USB flash drive to boot in traditional mode (do not use UEFI)] to reinstall Ubuntu. If it still appears after the reinstallation is completed, please do grub-install/dev/sda failednot Shut down the computer, repair grub directly , then unplug the USB flash drive and restart the computer.
fix grub
1. Install and start boot-repair
sudo add-apt-repository ppa:yannubuntu/boot-repair
sudo apt-get update
sudo apt-get install -y boot-repair && boot-repair
2. Use boot-repair to repair grub startup items
recommended repairAutomatically perform repairs with a click
The dividing line, below is the dual-system installation process under the conditions [currently it is a GPT partition, and UEFI is turned on in Bios]
Install Ubuntu22.04 from USB flash drive:
1. Under Win system, use ventoy software to make a boot disk.
2. Under Win system, compress the hard disk to more than 50G space (the bigger, the better), or directly install a new hard disk. The latter is recommended.
3. Plug in the USB flash drive, restart the computer, press F11 to select the USB flash drive to start, and officially start installing Ubuntu. The core of the Ubuntu installation process is partitioning. Apart from partitioning, other steps will not be described in this article. For specific recommended partitioning schemes, please refer to my other tutorial: Ubuntu22.04 LTS partitioning and configuration optimization (one step)