Tools: win 10 system computer step: 1. Open the win 10 system computer, enter the "Disk Cleanup" command in the Cortana search box in the lower left corner of the screen, and then press enter; 2. Select the drive letter to clean. The default value is the system drive letter. As shown in the figure, click OK. 3. Then the disk cleaning tool starts to calculate the available space and wait patiently for a period of time. 4. The space that can be released will be displayed after calculation. Click OK, and the tool will automatically clean up the selected deleted items. You can click the "Clean System Files" button here, and then the system files will also be listed in the cleanable options, which will clean up more space. However, it should be noted that once the "Windows.old" folder is checked, it cannot be rolled back to the previous system after cleaning.