In the Windows disc cleanup, those file should be deleted if you press OK. If they don't something is wrong indeed. Then just delete them yourself from Windows Explorer.
Lenovo Support Correspondence
Disk Cleanup Shows the following:
System Error Memory Dump Files 827MB
System archived windows error report 832MB
System Queued windows error report 40.3kb
Delivery optimization files 10.6MB
Temporary files 873MB
Disk cleanup went to completion… no change. Guidance sought

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