Because my Ubuntu system has installed a lot of software and modified many settings, I don't want to refresh the system for a long time, so I thought of how to generate an image for the existing system, in this way, even if you want to reinstall the system, you can use a custom image to directly install the system.
There are a lot of software on the network, but I use the remaster sys most easily. As shown in the following figure, step by step after startup.
An ISO file is generated. Now reinstall the system and use a USB flash drive. Most computers support multi-USB flash drives. It is a good choice to use universal-usb-installer-1.9.2.6.exe to create a boot USB disk. Note that because the name is inconsistent with the ISO file name in the list, if you select the Ubuntu ISO system, you will not be able to see the generated ISO file. In this case, select unlisted ISO, select from the directory as follows:
Click "CREATE" and wait patiently.