Generally...a log file is created by Windows...to provide an audit trail for review...if a user wants to conduct a review of a given event/process.
Windows Error Reporting and Memory Dump files...are potentially crucial when attempting to troubleshoot known system issues, IMO.
Not sure what "log files" might be...I've never had the inclination to use such because I don't have the brain power to troubleshoot complex problems (e.g., chkdsk logs) but I would leave such alone since they might be useful to those who are more adept at troubleshooting system issues.
I cannot think of a valid reason for ever deleting the above-named files...log files are generally tiny and do not themselves normally present any system problems...and they are created with the intent of being potentially helpful. The developers of Windows are far more intelligent than I...I assume that such knowledge is reflected in the creation of "log files."
Do not invoke the "registry cleaner" function of Ccleaner.
Temporary files can (and should be) routinely deleted. Such may often be a locus of adware/malware. See Ken Blake comments at Answers, Microsoft.com .
Edited by hamluis, 09 April 2018 - 07:37 AM.