Make a complete notebook backup?

I have a very old computer here that has not been used for a long time.
Standard operating system Vista, so that should say something to shcon.

Well, I don't intend to use it for anything dramatic either, just let me run a few programs non-stop.

The only problem is that it is currently more than lame (wait several minutes until it reacts to something at all) so there would probably only be complete flat as an option to get it back to halfway normal runtimes.

Only a lot of important things are stored directly and indirectly on the computer.
Be it important text documents hidden in some sub-folders, saved browser data and passwords, etc.

That's why I would like to save these things externally before I destroy it.
It just becomes difficult to really think of everything that could be on it and could be important.

So I would like to know whether it is somehow possible to simply copy the entire computer content 1 to 1 onto an external hard drive or something?
Of course I have to muck it out at some point.
But it just means that I can simply set up the notebook from scratch without worrying about not having backed up data and something will be lost.

What are the options?

Get an external hard drive. You get it pretty cheap.

Then you just have to go through what you want to secure.

e.g. Pictures, documents, songs, videos. Also certain exe files or program settings.

Yes, you can clone the hard disk or make an .iso backup from the hard disk.

That's it, I would like to save everything.
Of course I have to muck out the hard drive by hand at some point, but for now I would just like to save EVERYTHING that is on the notebook. Data, information, etc.
Without creating an unsystematic site where I forgot to save something in the end and only notice it afterwards

That's the question, but is there really anything on the hard drive that is somehow stored in the computer?
Because I mean, with a cell phone there are de facto 3 storage locations:
(optional) sd card, internal phone memory and sim card memory.

it's not all bundled in one place, at least usually.

When the hard drive is cloned, have I backed up everything that somehow exists on the computer?
Will the registry and something like that be copied 1 to 1?

Yes, everything is on there. Every sector, every file, everything.