My PC's Disk Defragmenter doesn't respond when I click "Analyze" or "Defragment" but it responds to other options such as "customize view" and so on. Other than the Disk Defragmenter(Dfrg.msc), I had installed IObit Smart Defrag, but I'm sure it's not the problem. I think the problem is related to the setting of services in Computer Management, but I do not know which service.