I just downloaded CCleaner trial version. I had to restore my computer back a couple of weeks, and now am getting these error messages on startup. I have been on one problem or another for 2 weeks and every day it's something different. I notice CCleaner has a Tray Notification cache cleaner, but also has a warning about Internet Explorer. I don't understand what it means to restart Windows Explorer process. Any help out there for a rookie?
Tray Notifications cache will be cleaned after a re-boot as that will restart Win Explorer.
The other way is through the taskmanager but as you need to ask about this, that may not be a good way for you to do it.
Do not leave Tray Notification ticked as it will always want you to re-start Win Explorer after a clean.
It would be best for now if you untick all monitoring until you find your feet with CCleaner. (it will pop up a warning but it's safe to go ahead and turn it off)
This page shows you how to do it in the paid version as you said you are on a trial