1. Use the system's own cleaning standard to clean disk C.. First, right-click the properties of drive C, then open it and click Disk Cleanup. Finally, check the scan results and click Clear.

2. Clean up the startup items. First, click Run at the beginning, then enter MSConfig during running and click OK, then check the antivirus and input methods, click Start, and then restart the computer.

3. Use the third-party software 360 security guard plug-in function to clean up. First open 360 Security Guard, then click "More" in the lower right corner, and then click "C Disk Move" and "System Disk Slimming".

4. Manual cleaning. Open drive C and cut the software, video, MP3 and document downloaded and stored in drive C to other drive letters.