This is normal. Don't worry, after installing the software, some necessary files, such as the registry and some startup files, will be installed on the system disk. In addition, according to different software, some software is automatically updated. Sometimes the default installation path of these automatically updated files is also the system disk, and some temporary files will be generated during the software execution. Some software will automatically delete these temporary files when exiting the system disk. But sometimes it is necessary to manually delete temporary files. Some network players, such as pplive, will generate a file with the capacity of 1g on drive C after installation to store the temporarily downloaded files. Therefore, it is suggested to regularly clean up the junk files and temporary files in the system to help the system drive slimming.