Why do I not see the ccleaner app anywhere after downloading. I see it in my programs but when I click to open it defaults to a Windows cannot open this app etc...
We need a bit more information.
What you describe looks like a Windows version issue.
(Maybe you have Windows 10 but set for compatibility with an earlier Windows version?)
We'll assume that this is a new CCleaner download so v5.65.
Which Windows version are you using? Is it set for compatability with an earlier version?
Which anti virus are you using?