i wanted to let everyone know..
i decided to try out using a particular software-program, the "binisoft windows firewall control" program, and it said that it needed for the windows "DNS client" service to be running in order for it to function properly, in order for its "event-logging" to function properly, that is.
i had the "DNS client" service disabled since it needs to be disabled when using a large HOSTS file, which i used.
i went ahead and installed the "binisoft windows firewall control" program and i could see that the program was not properly logging "events" due to the fact that the windows "DNS client" service was disabled.
so, eventually, i decided to re-enable the DNS client service, along with some other, related windows services that i also had disabled.
the main point: after re-enabling the windows "DNS client" service, along with re-enabling some other, related windows services that i had disabled, ccleaner's "software updater," in cccleaner's "tools," was back to functioning properly.
i should also mention that, since i had re-enabled the windows "DNS client" service, i had to remove the "HOSTS" file that i was using. the HOSTS file that i was using also could have been part of causing the problem where ccleaner's "software updater" feature was not working properly.
i've noticed that, with windows 10, and i believe that it was the same with windows 7, microsoft tries to make it impossible to disable the windows "DNS client" service. so, i consider that, that microsoft does not want people disabling the windows "DNS client" service.