When I click on Software Update it says Security Update for Microsoft Defender KB2267602 will not install. I checked Windows Update and it says everything is up to date. Do you know any solution to this problem?
That particular KB update has been a problem for some for a while now (at least a year).
See if any of this helps: KB2267602 Fails to Install: Here Is How to Fix It!
Being frank here I am not a fan of CCleaner Software Updater now offering Windows Updates - to me that should be left to Windows Update and not something that CCleaner should be doing.