Hello, brothers and sisters!
I am a new user and I cannot figure out how to select all duplicates with 1 click.
I will be clicking to select thousands of individual files for ages if I must go 1 at a time.
Please tell me there is something simple I am missing, and then tell me what it is!!... <span class="ipsEmoji">?</span>
The Duplicate Finder is deliberately designed that way to prevent you from making errors that could break your computer.
The CCleaner duplicate finder is more powerful than other duplicate photo finder, duplicate document finder, etc. applications.
Rather than being limited to specific filetypes, (in the way that photo finder apps only compare image formats), CCleaner's Duplicate Finder can find duplicates of any file, including the Operating System files, and so you have to be more careful when using it.
From what you say about "thousands of individual files" then I believe that you may have beeen about to make an error that could have had serious consequences.
Many system files need duplicates in different places, and if you delete those duplicates some things on your computer may/will stop working properly.
If you are getting thousands of results then you probably need to be more selective in your searching for duplicates, eg. restrict the search to your own files and not the System Files, have a read here for some advice on using the Duplicate Finder safetly: