Reinstalling the system requires formatting the original system disk (usually disk C). After formatting, everything in it is gone, but the contents of other disks will not be lost. However, if the program that starts these contents is installed under drive C, it needs to be installed separately in the future. Therefore, if you have the information you need on disk C, you should move ahead of time, move to another disk or choose other backup methods, such as collected study materials, downloaded materials, or do it yourself. As for other applications, you can reinstall the system before adding it.