After updating the nvidia driver, I restarted the computer and it could not be opened. The screen was black and only a horizontal bar flashed in the upper left corner.
None of the online methods were successful, so I decided to reinstall the system.
1. Save the file
1. Turn on the computer and insert the USB flash drive
In the black screen interface, ctrl+alt+F1 enters tty, and enters the user account and password.
2. View disk information df command (for viewing only)
df3. Determine the files you want to copy
cd /home/用户名/Desktop 等不同目录中查看文件（Documents、Downloads）
ls 查看文件信息4. Mount the USB disk
sudo fdisk -l 这将列出所有已挂载的块设备及其分区，包括 U 盘。
通常，U 盘会以类似于 /dev/sdX 的标识符出现，其中 "X" 代表不同的字母（如 /dev/sdb）。
mount /dev/sdb1 /mnt 挂载U盘在/mnt下
cd /mnt 进入U盘
ls 查看U盘中的内容
5. Copy files to USB drive
cp 源文件 /mnt
cp -r 源目录 /mnt6. Exit the USB disk
cd ~ 退出当前目录
umount /mnt 卸载U盘2. Prepare Ubuntu system disk
1. Obtain Ubuntu installation media
Prepare a USB flash drive as the system disk and download the latest version of Ubuntu installation image. You can find the corresponding ISO image file on the Ubuntu official website. Once downloaded, you can burn it to a disc or create a bootable USB.
See online teaching guide
2. Insert the installation media
Insert the Ubuntu installation CD or boot USB you created into your computer.
3. Install Ubuntu
follow the process
First select the language - Chinese, then choose to install ubuntu, minimal installation
Note that if it has been installed before, choose to uninstall and reinstall it.
Set account password and wait for installation
After restarting, the installation is complete!
4. Change the Chinese input method
Click zh in the upper right corner and select the second "Chinese (pinyin)"